> For example I vant to download all *.jpg bigger than
> 50kb and smaller than 100kb and *.zip biger than
> 10mb and smaller than 20mb

See:
<http://www.httrack.com/html/filters.html>
"1.b. Scan rules based on size"

In your case:
-*.jpg -*.zip +*.jpg*[>50<100] +*.zip*[>10000<20000]

(remember that the last scan rule always win)