I was messing with this for a few weeks already, i decided to gave it another try today. The first few renders of a socom mk-23 i modeled dindt came out well.
So i build up a scene from scratch wiht a plane and 2 boxes, amplified the light by 200000 and ......it worked!
Here is some info from the guy whom made this possible and a tutorial:
http://kupio.lunarpages.com/~tru7h02/halo/gmax_render/
And here are my results: