I have used this utility before look at
http://www.dos2usb.com/index.htm
I have had mixed results - i.e works most of the time in XP - not tried this on Vista or 7
Net Use LPT1 \\ComputerName\Printer_Name /Persistent:Yes
I believe the printer has to be shared
or something I have not tried is vbscript :-
WshNetwork.AddPrinterConnection
other than these I cannot think of anything else - sorry :(