Per-user packet filtering - is it possible?

Hello,
I have a Solaris 9 machine with IPfilter installed. The machine is NOT a
router, ie. IPfilter is used only to filter connections to/from that
machine.
I'd like to allow only certain local users to connect to certain addresses,
ie. filter outgoing connections so that for example "user1", logged on the
machine, can telnet to address x.x.x.x, but "user2" cannot.
Can this be done with IPfilter, maybe with the "auth" rules? The "auth" and
"preauth" options are almost undocumented, so, if it can be done at all,
could anybody explain me in detail how to do it?
Regards,
Jaroslaw Rafa
raj@ap.krakow.pl