Getting miscellaneous emulator functions to work with gamepads

I basically have a home theater pc, and want to be able to map emulator functions such as save-state, load-state, turbo, and exit from emulator to my gamepad and not have to use a keyboard at all. I've gotten this to work in znes and nestopia, but mapping those functions to others such as virtual boy advance or project64 is not supported. The gamepad drivers i am using support mapping certain buttons to keyboard keys, but the many of the keys are emulator specific, ie the save-state button in p64 is f5, while it is shift-f1 in VBA.

Does anyone know a way around this, or maybe some program that will detect whatever emulator is running and change the special keys accordingly?