I think at this stage what you wish to do is not possible.  HTTrack needs to
"download" pages from a website to then scan them for links, images, etc. 
After it's downloaded them it just saves them.

You could capture a site, but then afterwards just delete everything you don't
want using DOS (if you're on Windows), eg:

c:
cd "my web sites"
del /S *.html *.htm