Bose Soundtouch Volume Control w/ Remote?

I’m looking to find a way to control a Bose Soundtouch Wireless Link (attached) using a z-wave remote control button. I’d like one button to turn the power on / off (already can do that) but also increase and decrease volume.

Is there any way to link volume control to a button? I’ve looked in the existing smart apps and can’t find this functionality… FYI volume control is available in the device handler already for Bose, but just not linking it to a button press.

Thank you for your help…