Data editing (Far Cry 2)

There is a need to edit the characteristics of weapons in FC2 and the possibility to realize some ideas. Ready fashion not good for me. Peresherstit the Internet far and wide, I found Nothing. No information. But mods different from our countrymen on FC2 a lot, their authors never said a word, they were able to edit the database. I have learned only one thing : everything editable is the file format .dat and fat. Any kind of universal extractor failed miserably with the task to unpack them. Also in the vastness of the site found a Far Cry Archive Viewer, which with grief in half can unzip, but the back pack can't. With his help, I extracted the config from the patch.dat , found and edited what you need, however, then what to do? To pack, as I said, the program can not... please Tell me how to solve this problem and make the finally edits in the game.