Draw or render a preview of a scene into a bitmap value

Hi guys !
I am french so, I'll try to do my best to ask my question in english correctly :D. Be kind :P.

I am actually working on a little animation tool to copy/paste positions of bones.
My primary reference is the copy/paste tool of the Biped (Character Studio).
Which containt 2 very interesting things:
- some kind of listbox UI, where you can rename your selection (do someone know how to do that in maxscript?).
- and, the most important for this topic today: a little preview of the pose copied.
- http://diccy91.free.fr/copyPaste_biped.PNG -

I really don't know how it is done. I tried to do something like this, with vertex position based pixel drawing, but I did it in a really shitty way I think.
- http://diccy91.free.fr/copierColler_diccy.PNG -
I could be happy with it, it is functional, readable, quite user friendly. But, actually all the rig is "drawn", even what is outside the picture. So, it is really not optimized...
So, I tried some checks, what is in the camera view, what is outside, and all that stuff... But it was more complicated than I expected.
Looking back to the Biped's tool picture captured, I told to myself they might use some max rendering to make it, not themseves (as I tried to do).

I searched in the Maxscript Help, but didn't find what I was looking for. As I didn't know what I was really looking for :D! So here comes my question: do someone have an idea how they get that kind of picture, maybe using max rendering methods in maxscript? And which ones?

Good evening ;).