We need to be able to manually set a username for the Iprint-client in OS X, other than the username OS X reports, alternatively be able to change the username of the logged in user temporarily while logged in.
Is there a solution for this?

When our students log into a Mac in our computer labs, due to peculiarities in our setup and in how OS X handles usernames at login, everyone get the same local username instead of their real Novell username. I haven't found any practical way to get around this.
Due to this, print quota doesn't work on our Iprint-queues, since Iprint automatically reports the local username.

I've tried having a login-script, run via a LoginHook, that set the USER, USERNAME and LOGNAME to the Novell username, but apparently this doesn't affect the entire system.

We're using Iprint client 5.00 and OS X 10.5.8 and 10.6.4