Need printer login script

Hello all ? I need a simple login script to set printers already installed on a Citrix/Terminals server as default printers for certain groups. The printers are installed on the Citrix/Terminal server as TCP/IP ports. When the user logs on, I would like for the script to set one of these printers as the default printer for that user. The script will be stored in Group Policy and applied to the appropriate OU. Thanks in advance for your help. RC