I'd say there's no need to intercept packages. Try googling 'Oblivion Script Extender', 'Oblivion Graphics Extender' or anything similar for its prequel. Both of those don't touch the game's (TES IV: Oblivion, in this case) executable, but they provide more variables/functions/etc. to play with for scripts, allow new shaders, supply information from the game TO shaders, etc. http://cs.elderscrolls.com/constwiki/index.php/Category:Oblivion_Script_Extender