> > *foo=*[0-9]* should do what you want.  What are
> your
> > other filters?  Do you have a -*foo=* above
> 
> WildCardFilters=-* +*index.php*cat=*[0-9]*
> +*thumbnails.php*album=*[0-9]*
> +*displayimage.php*album=*[0-9]*
> +displayimage.php*fullsize* -*sort=* -*.jpg -*.gif
> -*.png -*.css -*slideshow*
> 
> With this filter httrack happily includes URLs like
> .../thumbnails.php?album=topn&cat=0 which to me
> seems buggy.

Thumbnails.php*album=*[0-9]* matches thumnails.php?album=topn... 

The *[0-9] matches nothing and the last asterisk matches the topn.  

The manual says * matches 0 or more.  

If you want album=999 you need *album=*[0-9]