To add a network printer from command line
To run a command from machine on which printer needs to be added
rundll32 printui.dll,PrintUIEntry /in /n \\PRINTSERVER\NETWORKPRINTER
To run a command from server or other machine on network
rundll32 printui.dll,PrintUIEntry /in /c\\CLIENTMACHINETOINSTALLON /n \\PRINTSERVER\NETWORKPRINTER