Now, I know nothing about 3D modelling, however, I really want B.J. Blazkowicz from RtCW in Quake 3. This has been a nagging issue for me for a year or so, and so I decided to ask you guys. Is there a simple way to do this?

There's no easy way to do this. The games use different sets of animations and the model formats are quite different ( RtCW -> mds Q3a -> md3). BJ would have to be adapted to Q3a.

This is something a dedicated hobbyist can do however. I'm pretty sure I've seen adapted Jedi Outcast models (ghoul2) for Q3a floating around.

Hmm, that's what I was worried about. Like I said, I know absolutely nothing about this subject.

If I could get the model converted to md3, would it be possible to just use the animation from somebody else in the game, such as Sarge, or is there some thing I'm not getting with how this works?