Printing for a DOS-based app

I have a DOS-based app with which I am having problems
printing. I am able to go to a dos prompt and type NET
USE \\servername\sharename LPT1 and use one of the
printers. But that printer is in another building and no
one wants to walk to the other building to get the
printouts. When I do a NET USE for the departmental
printer and then try to print, I get an Access is Denied
message. What is causing this?

I am able to print to any of the 3 printers from Windows
and I compared the settings on the server and all 3
shared printers appear to be configured similarly.

Ken