how to pass username/password to a network printer

Working at a client site and their printers require username/pwd. I've
been given one.

I can ping the printers, so went ahead and added using "add new TCP/IP
port" in add printer wizard. Specified the correct driver also.

Problem is that nowhere during the install process did it allow me to
specify username/pwd combo. When I print a test page, job goes off into
nowhere land. Appears to have succeeded, but nothing comes out of the
printer.

How can I pass a username/pwd to the printer? I suspect it's using my
default XP username/pwd, which obviously won't work.

thanks.

c