Make sure that you take a look at Dave Musgrave’s latest post where he explains the ins and outs of using Named Printers on a terminal server. Dave even links to a GP paper he wrote with step by step instructions. Very nice Dave! I suspect that this will bail be me out of a jam or two in the future.
Dynamics GP Named Printers on a Terminal Server
Archived post from 2008. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.