> how can I force HTTracks to read in directories for 
more files which are not directly linked in html-files?> for example:
> <http://rfhs8012.fh>-
regensburg.de/~saj39122/TRON/applet.html
> starts java applet 'tron.class' which is located in
> <http://rfhs8012.fh-regensburg.de/~saj39122/TRON/tron>
> HTTracks download only '/tron/Tron.class' and ignore 
> /tron/Player.class
>...

Just add the URL <http://rfhs8012.fh>-
regensburg.de/~saj39122/TRON/tron together with the 
first URL you specified for the download.
But this may not work, if the java applet is calling 
directly a remote class.