Making impossible change proxy settings, even on dial-up connectio

i'm trying to use the policy to make proxy settings to a machine-level
config, even on dial-up connections

i have a notebook that can connect to internet in hotel rooms or in the home
environment, via ISPs in any city dialing a local telephone number. But i
would like to "force" the user to use ALWAYS my internal proxy server.

The problem: In a LAN, the notebooks connect to internet via a local proxy.
When they're out of the company they connect first via a local ISP and after
connected to the local ISP, they use a VPN client to connecto to the
corporate environment. The problem resides in the fact that before the vpn
connection, he can navigate in the internet to any web site, wthout any
control by my local proxy (internal) Before the VPN be opened, he have
unrestricted access to the internet.

When i use the option to "force" a proxy setting at the machine-level, it
does not
work for dial-up connections. The dial-up connections still have their own
proxy settings, bypassing the local proxy (my desktops and notebooks, when
connected in my LAN have a Proxy Setting configured via group Policy),



.