proxy repeater + script configuration file

Hi:

Here I have 9 PC's in a private network. Their interface with the
outside world is through one of the PC's who has an extra network card
connected to the internal network of my company. Everyone who wants to
connect to the Internet has to configure his browser to accept a
proxy.pac configuration file.

I'm now using a proxy repeater (stone) to surf the web from the
isolated machines. Since I don't know how to configure stone to use the
proxy.pac file I use the IP and port number of the proxy server. It
works OK, but I can't access anything inside the intranet.

I would like to configure stone to accept the proxy.pac file or
otherwise get a better proxy repeater that allows me to do it. Any
suggestion in both ways will be wellcome.

Kind regards,

Sergio