Kyle,
Do you know what RF frequency the current remote control uses? I added support to my Arduino ST_Anything project to support an RCSwitch which may be exactly what you’re looking for. Take a look at
Announcing the “ST_Anything” Arduino/ThingShield Project. Basically you buy a very inexpensive RF Receiver to capture the RF codes transmitted by the original remote. Then you use a corresponding RF Transmitter to send the RF command specific to the function you want. You also need the ST ThingShield to communicate with your hub.
Hope this helps. I think it is a much cleaner solution as the original remote does not need to be hacked at all. Turning the RCSwitch “On” simply sends the corresponding RF command, and the same happens for an “Off” command (with a different RF command of course.)
Here’s a link to a 433Mhz version of the transmitter/receiver pair. http://amzn.com/B00M2CUALS
Dan