

All LUA script calls will have their mechanism of doing in GTA what the script tells them, you can take that code or just same approach to mod SA with it. So if you're both a good GTA modder and understand LUA scripting, you can make a list of what exactly the scripting LUA function represents: then get the C++ code from MTA:SA opensource for that LUA function, and watch how it does that in GTA.

Until a certain level it's surely possible, because every scripting function in MTA (lua code) represents changing something in the GTA SA engine.
