Can someone explain how one can select the sound card stereo mix output as
the audio source when capturing a home movie from a composite/ s-video analog
capture card ( only has S-video or composite ports on it).

I don't have the luxury of a second camera with firewire passthrough
capabilities.

I have read where one can opt to select the sound card as the audio source
with a capture card like the one described so that the analog camera can have
the audio outputs fed into the sound card line input and the video input
through the capture card.

Makes sense, and would seem to be a lot less trouble than recording the
audio separately and trying to sychonize lips to audio in movie maker.