hey first off perx is fine i use it and works everytime crashes a litle here and there but idc it works.
1pen perx and inject place type Engine.exe
2: look for injecting file i.e that hack you want to inject to tha game
3:hit automatically
4:start combat arms normally and hack should work.
note: use arrow keys to navigate and turn hacks on/off rapid fire is a little buggy with knife