You have to make the KSU transfer each different incoming fax to the same place to be routed later. You'll have to convince the KSU that incoming fax digits are actually mailbox numbers, but not necessarily system extension numbers. Give this a try--

Make your fax server analog port(s) a voicemail port and put it in one of the extra voicemail hunt groups.. 49, 50 or 51. Depending upon which group you use, enter the Feature Access (Class 7)code related to that group in the Conversion Number column in class 25 for whatever incoming fax digits you'll be receiving. Put the fax box number the server will be looking to route to in the MBOX/NSC/ACD column. You'll have to instruct your fax server to disregard the first digit it sees - Vmail packet number- and use the ensueing digits to route to a particular fax.

Sometimes the thoughts in my head get so bored, they go for a stroll through my mouth. This is rarely a good thing.