I can’t find it mentioned in the documentation but Wavelab 8.5/32 bit/Win7 can extract the audio track of some video files. It’s worked for me on a Windows WMV video file and an .m4v file. I haven’t tested the quality or stability of this method (i.e. it’s an undocumented feature so might not behave as expected) but it does work. Doesn’t edit the video at the same time though! Just try opening the video file in WL and see what happens.
For the task you’re describing I use an custom ffmpeg script placed in the Windows “send to” folder. This work brilliantly, as I can right click and instantly strip the audio off most video files.