Hello bb193,
I had a similar question recently. The thread is
here
I would use video redo to do this. I save the audio stream and throw the video away. The audio can go into windows media player and expanded out to go on a CD. Of course you are losing some quality if you are compressing and expanding again. I have left the audio as a .wav file for listening.
I don't think that windows Movie maker will allow you to save as anything other than a windows movie maker file, .MSWMM, which seems to limit its usefullness somewhat.
I don't know about NERO, but it may have a similar functionality. Ulead video studio does, and I have also used that successfully.
I hope that this helps.
King Hilary.