[THIN] How to set Windows Terminal Server to use client MAC address

Hi,

My scenario is I have a few Windows XP PCs. Users use these PCs to connect to Internet. When connecting to Internet, the traffic will go to a hardware gateway controller and a login page is displayed to client browser for sign in. Upon successful sign in, the gateway controller will allow the PC connect to Internet. The controller done this by recognizing the mac address of the PC who sign in.

I'm moving the above into MS Windows Terminal Services (using win server 2003) environment. However, whenever the PC remote desktop to the server and use the browser to connect to Internet, the gateway controller will get the mac address of the server itself instead of the PC that is remote desktoping.

So, I wonder if there is anyway to configure the server to use the mac address of the PC for further connection / traffic.

Thanks.