Dial Up Networking issue in Vista

Thinkpad R60
Windows Vista Business
PCMCIA CDMA 1x dial up modem
Domain network on Wireless using built in adapter

I am facing issues that currently I am connected to internet using the CDMA
dial up modem, as our office broadband connection is down. When I connect to
the dial up connection, it shows Access: Local and Internet, while the
Wireless shows Access: Local. The problem is that I am not able to disallow
the local access to the dial up. This disconnects me from my domain network
and changes the route to go first thru the dial up.

I want to know how I can configure the Dial up connection only to route
internet traffic and all local traffic to go through the wireless to my
domain network.

Thanks.