Limit specific machine to one website

I need to limit one machine (static IP) so that it can only access one or two web sites and is blocked from all other web activity.

While this is easy to do using firewall rules, my use of web filtering bypasses the firewall.

I don't have any users defined - in the case of this machine it is non-interactive, so it isn't possible to have it log in as a user.

How can I set up web filtering to accomplish this?

Thanks!