> I want to download only the German branch of a
> website, so I enter www.xyz.com/de as start address.
> How can I keep httrack from going up and into other
> language branches like www.xyz.com/en ??  

By default, HTT goes down only, but it doesn't think de/../en is up.
Just add a filter: -* +*/de/*
Add the near flag (get non-html related) to get css/js/image files.