If you know the port either lpt1 if local or an ip address or share on a network you can make a simple batch routine that will copy files to that port.
copy c:\plotfiles\*.plt lpt1
copy c:\plotfiles\*.plt \\Servername\Printersharename
use quotes if you have spaces in any directory name.
you could add
del c:\plotfiles\*.plt
to flush the folder
or a rename if you wanted them to be saved for archive purpose.
Kepp this batch file on his desktop and he would be good to go.
If you ever place images in your files, you need a /b option
between the first part and the destination.
Pieter