Yeah, you must have programming experience. You must download the MP source code. Then you must recompile it.
(If this was medal of honor, it would be so much earier to do. but rtcw doesnt have an open system to edit.)
As far as being able to do what you wanted, sure its possible. Headshots take the weapon damage and multiplies it basically.
You can do anything with the code, you just have to get really good at programming.
:(,r there n e dowloads, progs or tuts?