I can only use: 
+www.yousite.com/*.jpg

since I do not know the names of the files in advance, 
however, what I am unclear about is whether httracker will 
download every .jpg in the directory OR only every .jpg in 
the directory that is REFERRED TO to in the HTML file you 
are trying to mirror? I only want files referred to in the 
html file I am downloading...

Also I have one more question:

Does httrack follow <base href> tages correctly? Namely if 
a document has a base href tag, what option must exist so 
that the page is downloaded in such a way that images on 
that page that come from this tag are downloaded as well? 

Thanks.