Teni I have known a couple of Doms who use wheelchairs and still find ways to incorperate BDSM into their life. There have been some great suggestions so far, let me share a few observations on what they have done.

First there is a much heavier reliance on the mental aspects of the lifestyle and and their style has switched from physically oriented play to that of service and submission.

A few suggestions come to mind from watching them. One is control of things such as style of dress and presentation such as collars and other symbols. I'm sure he has some opinions along this area. Lucy has some good thoughts here. They both incorperated self bondage with the sub putting on collor and cuffs with chains with the Dom holding the keys. I fondly remember a night when one of them was leading several subs on leashes arround the dungeon and its halls at an event. Also one Dom incorperated sexual control in the form of a chastity belt and remote controlled toys which fits with your push button idea. Wizard's suggestion of adding pony play is a great one too.

Lastly both were able to inlist other Doms to participate in scenes with them to add back in some of the physical play that had been lost. I don't know if any of these would work for you though.