AMalgamating

[exalos]

I don't know what format is your sound, so read on:
If your sound is in .ac3 then you should use a program like "Besweet" to convert the sound to mp3 and then using "wavemp3" make it a fake wav-mp3 so that you can use it with "virtual-dub" later on.
You open the movie with virtual-dub and then you add the sound by selecting at the audio menu - wav. then you save your movie and you're done. You have a movie with sound!
If your movie is already mp3 you just do the same as above without having to do the first part (ac3-->mp3).
Hope I helped you.