Printing using lpr to local remapped printer

I have a WindowsXP with installed print services for UNIX. A remote
machine prints to this printer using lpr. If the printer is attached to
FILE: printing works well asking me where to save the output.

I want to attach the printer to a network printer at a remote print
server. I can't map the shared printer because after that there is a
blank in the printername (eg. "printer at spoolserver"). This name is
not working with lpr. To avoid this I mapped the remote printer to ltp3
using 'net use lpt3: \\spoolserver\printer'. This works perfectly when
printing a test page from the XP machine itself. But if I print to that
printer remotely using lpr an error message occurs (unfortunately one of
the MS type - "There were errors printing ...").

Is there any ideas what to try or where to look?

Pit