Question About Effect Shaders

[Omny]

Is there a way to apply an effect shader to only part of an NPC's body? Like, say I wanted to add an effect shader to an NPC, but not their hat. How would I set the shader properties in GECK or NifSkope to effect everything except their hat? Would I have to add some particular kind of shader flag to the hat itself?

 

I've tried looking up info on shader flags online, but as far as I can tell there's no tutorial or anything that tells you exactly what each flag does. Like, what is "zBuffer Test", or a "Premult Alpha"? The "Interactive Help" is completely useless. You'd think that a modding tool that's been around for like ten years would have some more info on how the hell it works!