For a number of technical reasons, that’s not going to happen, unfortunately.
There are things that you can do to try to reduce the barriers.
First, if you have a light fixture in the ceiling, put A zwave lightbulb in it. That’s not going to give you the beaming that you need to get to the lock, but it may let Zwave signals travel the length of the garage. The most important thing is it’s up above the level of the automobiles and freezers and most of the other stuff in garages that can block signal.
Put a beaming mains-powered device very close to the lock. That will usually be a pocket socket, but it could be a wired receptacle or a light switch. Note that you can even use a pocket socket on an extension cord and it will still work as a repeater.
OK, those two things together should mean that if a Z wave signal can get into the garage, it can get to the lock. Now you just have to get it through the wall.
Getting signal into the garage
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weather strip Some people just shave down one side of the door from the garage into the house, put regular rubber weatherstripping on it, and the signal can get through the weatherstripping where it couldn’t get through the door. You may need to put another Z wave device on the interior of the house fairly close to that door, but usually there’s a good place for those if you don’t already have one. Again, pocket socket, wired receptacle, relay, or light switch. This is probably the easiest solution, but because it requires modifying the existing door a lot of people don’t want to do it.
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Or add a repeater high up on the shared interior wall. Another alternative for some people is to plug an extension cord into an existing receptacle that is on the wall shared with the interior of the house, run that extension cord up the wall just about to the ceiling, and plug in a pocket socket there.
With this method you’re hoping that the Z wave signal can get through the wall at exactly that spot to that pocket socket, which will then repeat it to the lightbulb in the ceiling, which will then repeat it to the beaming repeater near the lock, which will then repeat it to the lock.
To find a good place to put it, take a battery powered Z wave sensor and hold it against the shared interior wall until you find a place where its signal gets through. You may have to try several places depending on what’s inside the wall. For example, a water pipe will probably block the signal. Then once you found a place, you can put the pocket socket there.
But there’s a problem here, which is another reason why Zigbee is sometimes a better answer.
Did you notice that we took three hops just to get across the garage to the door lock? First pocket socket to lightbulb to beaming repeater to lock. Zwave has a maximum of four Hops for any one message, which means it has to be the hub itself that is talking to that pocket socket on The shared interior wall.
Zigbee allows for more hops, which is why you often find zigbee devices working in places where Zwave devices don’t, just because you had to use a couple of hops to get around physical obstacles.
But maybe you don’t need the lightbulb. If you don’t have shelves or other things hanging on the walls, you might be able to skip using the lightbulb if you have both repeaters (the one on the shared interior wall and the beaming one near the lock) with clear line of sight to each other. You might not even need an extension cord with the one on the shared interior wall if there’s a wire receptacle on that wall with clear line of sight to the beaming repeater. (As I mentioned, garages are a bear.)
The problem is that most garages do have stuff along the walls. Or the receptacle on the shared interior wall is far enough over that there’s no clear line of sight to the beaming repeater. But if you can make it, work go for it.
Also remember in all cases that if you pair these devices right next to the hub, you need to put them in their permanent locations, then run a zwave repair, and then wait until the next day to actually test. It takes time for the address table updates to propagate after The zwave repair utility completes.
In your case we have to use up an extra hop because of the beaming repeater required. If the end device wasn’t a zwave lock, we might not need the extra repeater close to the lock, which would save us both money and a hop. But because it’s a lock and Zwave lightbulbs don’t typically support beaming, we need that extra device. Because probably the pocket socket on the shared interior wall will be too far away from the lock.
And we had to use three devices, which added together will probably cost almost as much is the zigbee lock.
( by the way, some lock manufacturers have interchangeable modules so that you can just take out the existing Z wave module and put in their Zigbee module. This saves you a lot of money because you’re not buying a whole new lock. You might check with your lock manufacturer to see if that’s an option For your model.)
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or reach the lock from outside the house and skip the garage interior altogether This is often a great option for Zigbee locks. You just put a $15 ZHA lightbulb ( directly connected to the ST hub) on the outside of the house. bounce the signal out the window to the bulb, then from the bulb to the lock.
But with a Z wave lock we run into that beaming requirement again. You may still be able to use it with an outdoor power receptacle that supports beaming, but placement can get trickier. Still, this is often an easier path than trying to get through the garage.
So those are just some additional things to try. Remember the four hop maximum, though, that trips up a lot of Zwave implementations.
I’m not sure what does Zigbee hop maximum is for smartthings (it can vary by controller), maybe @slagle can find out. 
Have you considered trying a Zigbee lock?
, but I have over $150 invested the Z-Wave lock I have now and I already have a working Z-Wave lock on the front of the house. It was too late to return the lock where I purchased it since I thought I could enhance my Z-Wave network to the garage with the Aeon Labs Aeotec Z-Wave Smart Switch 6, Gen5. Luckily, I was able to return that device… but I still have the college attitude to find a way to get signal out there.