Listen i didnt mean to offend you damn.. but i mean dont you see the fucking MW2 Hack Project Beta 3 INSTEAD OF 2!!!
Anyways you run the program while your in the lobby of the game (not in multiplayer; in the regular lobby that says "find game") then you go back to the program and then click on the name that you want and you can go back ingame do a couple rounds and lvl up or whatever then it'll be saved and boom you have a level
IF You are looking for the jump hacka nd stuff you must do a "private match" to do that sorry but either ways its same way except for the jump hack and stuff