> Is there a way using HTTrack just for a crawling process, 
> i.e. just getting a list of all urls (e.g. in a text 
file)?!

Set Options / Experts only / Primary Scan Rule : just scan
Links will be put in hts-cache/new.txt

If you also want external links, you'll have to code a 
small plugin to wrap fetched URLs. (see the httrack 
developper page, <http://www.httrack.com/html/dev.html>)