RealPort - change parameters using the command line (Windows) problem

How do you use the /change command in Windows? I installed my RealPort driver and deselected all the ports so I can configure them via the command line (I need to do this in a script). When I do something like this nothing happens:

setup.exe /change /ip=my_digi_ip /port=3:COM3

Am I doing something wrong? I would need to use my local COM3 to get to port#3 of my Digi TS (PortServer TS16) port server. When I use the mouse selecting the right checkbox in the Device Manager (WinXP), RP properties, everything works great so it’s not a problem of network or device configuration.

Thanks in advance for any ideas!

james