Search for RPM's

Hi All, Can someone give me a quick lesson on how to find rpm's on SuSE's site? I have the 7.2 cd's, but it seems that these cd's only contain a subset of the rpm's found on SuSE's site. For example, the expat rpm is on the site but not on my cd's. The real problem lies not in finding the rpm name, since all I have to do is list ftp://ftp.suse.com/pub/suse/i386/7.2/full-names/i386. But what do I do when I want to find the rpm that contains a certain file, say, libltdl.so.1 or libpq.so.2.1? I've tried to enter ftp://ftp.suse.com/pub/suse/i386/7.2/full-names/i386 into package manager but doesn't like that so there doesn't seem to be anyway to search for a file name. Thanks in advance. Tom