I found a JAVA applet on a page and HTTrack wrote in the 
mirrored file like this:
 
<APPLET ARCHIVE=http://aaa/bbb.jar 
codebase=http://aaa/ccc/ CODE="Bbb.class" ALIGN=MIDDLE 
WIDTH=300 HEIGHT=300 ALT="XXX">
<PARAM NAME="input_file" VALUE=http://aaa/ddd
<PARAM NAME="input_archive" VALUE=http://aaa/zip/eee.zip

The applet did not work. I downloaded the needed files 
manually (bbb.jar and eee.zip), I placed them in proper 
places (I have no idea why HTTrack ignored them) and I 
changed the code (inside the html file) manually into:
 
<APPLET ARCHIVE="bbb.jar" CODE="Bbb.class" ALIGN=MIDDLE 
WIDTH=300 HEIGHT=300 ALT="XXX">
<PARAM NAME="input_file" VALUE="ddd">
<PARAM NAME="input_archive" VALUE="zip/eee.zip">

and now all worked fine (i.e. the applet worked offline).

Note that I delete "codebase".
 
Grzegorz Jagodziñski