> I would like to translate these estensionless pages into 
> html pages: ei <http://www.domain.com/path/toc?node=1232223>
> --> <http://www.domain.com/path/1232223.html>
> I understand I can use a 'user defined site structure' 
that 
> would look like: %h%p/%[node].html
> However it doesn't work since my pages don't have 
> extension.

It should work - the extension stands for the "final" 
extension given by httrack after test (httrack should test 
the page type as the extension is unknown)
But remeber that other files have to be named too, and 
something like
%h%p/%n%[node].%t

might be better.

You can use the advanced variable extraction, too (see 
httrack --help), which is slightly more complex but allows 
more things.