There is a cheap controller sold by getto/wal-mart called a "Game Elements Recoil" that is absolute 10,000,000% garbage as a video game controller, but somehow works very well as a mouse and input unit. It has a utility that remaps the entire controller with button presses of the users choice. After programing, with the flip of a switch, it will go from garbage game controller not fit to play space invaders to a programmable pc input device. I have two of them in my apartment which I will be hacking up for the very purpose you speak of.
A word of warning, using these for gaming may be hazardous to your mental well being. Don't say I didn't warn you