I'm using WinHttrack 3.48-8 to download images from a web server and I'm having
a problem how to set the local filename.

The download url's look like this:
<http://www.zzz.com/ImageResize/Image.aspx?src=%2fImages%2f56d9d0fd-30cb-489b-84ae-fdcf7053c77d.png&xxx=56d9d0fd-30cb-489b-84ae-fdcf7053c77d.png>


I added the xxx parameter to use that as the local/downloaded file name but
when I go in to options + build to set user defined structure I cannot get it
to work. No matter what options I set the file names come up with something
like this: 
imaged232.png

But what I expected/want is:
56d9d0fd-30cb-489b-84ae-fdcf7053c77d.png

Options I have tried:
%[xxx::::]
%[xxx]
%xxx

Any help is appreciated.

Thanks/Max