How do I permanently add subtitles to avi files?

Hi all!
I'm kinda new to BSP (ver. 0.86-493).
I want to add subtitles to an avi movie, save it with the subs and then burn the movie (with nero or other apps) as VCD.
I can't figure out how to do that. Every time I add the subs to the movie I can watch it with subs, but when I save the file, it is saved without them (eventhough I marked "Draw subtitles to overlay surface").
What should I do?
Li