I have just started using the option for Build > User defined > 
%h%p/%n%[page].%t

which appears to be the GUI equivalent of the -N option.

The website I'm working with has multiple such query strings (though never
used together, as far as I can tell). So in addition to "page=" there's
"more=" and maybe others. In the GUI at any rate, I don't see a way to specify
more than one such query string. Is there such a way, or am I stuck?