Printing to Windows Printers on a Domain

Hi,

Please help if you can.

I'm a net admin at a school.

The Setup

We're running a Mac Lab of iMacs running 10.5.6 joined to a Windows Server 2003 domain. The idea is to give students an taste of what Mac has to offer and to skill them up in this area. I'm not a Mac user myself (yet) so this is quite a challenge for me.

All print jobs must be run through a Windows print server where our print monitoring software runs; the users must be authenticated on the domain.

The Problem

I have managed to get the printers connected in Mac OS, but when a student tries to print, they're prompted to authenticate.

The problem is that the username field is pre-populated with their Realname not their username. E.g. John Smith not j.smith

This is confusing for many students.

Is there a way to force MacOS to use the username (SAMID in Active Directory) instead of the Realname (Displayname in Active Directory).

Is this something to do with LDAPv3 attribute mappings?

Note:
Tried altering Active Directory's Displayname, but this had adverse affects on Exchange.

Any direction you could provide would be welcome.

Thanks