it depends on the link. If the link is absolute, it will work. if relative, it probably won't work.
absolute: h++p://www.finetunedmac.com/forums/ubbthreads.php?ubb=newreply&Board=18&Number=15780&what=showflat&fpart=1
relative: /forums/ubbthreads.php?ubb=newreply&Board=18&Number=15780&what=showflat&fpart=1
(they can also be relative to a particular directory on a server)
(wow you should see the mess ubb made when I tried changing http to htp)
