Specifies the shell from which the DVI printer driver should be launched.
Note that you must not specify the SCREEN parameter in the shell! This is done
by the SCREEN command. So don't use SHELL=CON://400/50/Title/SCREENShowDVI-PubScr,
e.g., use SCREEN=ShowDVI-PubScr SHELL=CON://400/50/Title instead.