Pretty sure you'd have to use CM to map them, or at least assign as a DX Device and Button. Then, if you wanted to go into whatever game to use the games interface to assign the button, you could. But, again, you'd have to assign the device/button in CM, save the .map, load the .map and exit CM for it to be seen in the game. Once the .map is downloaded and assigned to the device and CM is exited, there isn't any system drag or running in the background so there shouldn't be any worries about resources being used behind the scenes.