first of all, your use of "rom" is incorrect, rom is a type of memory, "Read Only Memory" infact i have no idea what you were talking about.
but anyways, i just remembered something i used to do with flight simulator, i think this is what marvo was talking about. if i find the files for the game, like the textures etc. i could get the code for it and alter it a bit, i think changing a guys looks is a bit much, but i could probably do all sorts of stuff. ill try it just now.