If there is ONLY one way to control a particular volume and the device uses RS232, and you can set a direct volume (ie turn it directly to -40db), you can use the flags method.
I've done this with a Denon receiver once. The receiver was NOT in a location where people could see or touch it...
I used a series of flags on the remote...
...couple a thumb tacks and a stick of double sided tape should hold this baby up...
