Tell us which game,
Perhaps there is some utility out there, but generally speaking mods tinker with certain files in certain folders, and every game has a different structure, file naming and such, so logic says.. we need to know the game to look up how to mod that game.
Keep that in mind for future posts, it's better to give irrelevant information than giving little to no information when asking for help. I think that applies in life in general not just GBAtemp lol