Take a look @ the material file "vp_materials.mtr" in pak000.pk4/materials. It's all special effect material, VERY nice to pick apart & learn from.
Basicly, you need to add a stage like this:
vertexParm 0 time * 0.1 , time * 0.5 // texture scrolling
vertexParm 1 .2 // magnitude of the distortion
fragmentMap 0 _currentRender
fragmentMap 1 textures/sfx/vpstatic.tga // the normal map for distortion
vertexProgram = the heathaze effect
vertexParm 0 = how fast it moves
vertexParm 1 = the amount of distortion
fragmentProgram = the heathaze again
fragmentMap 0 = the texture to apply it to (_currentRender is what's on screen at the moment, so it distorts the screen)
fragmentMap 1 = the texture to apply for the distortion.
It would go in the material file for the material of the plasma bolt that flies. I think it's a particle so you'd need to look at the particle file for the material name to put it in.