You could, in theory, do anything you want... You can change ingame values to anything you want, but you have to find them. Example: flyhack is made in this way. "server hack" in that way too (it's not really a server hack).
I don't think it would work for CrossFire, because the bypass is not made for that game. But with a bypass that works with CrossFire (if CrossFire has a anti-hack system, I don't play this game), yes you could use Cheat Engine with it.
Ok the package is done.