I have a home LAN behind a Linux firewall connected to the Internet. The firewall also has a VPN connection to a remote host that can route traffic from the VPN to its Internet connection with NAT.
I want to configure the firewall to route the default (i.e. non-local) traffic of a specific host on the home LAN to the VPN rather than the Internet connection of the firewall which is shared by all other local hosts. This is to work around country-IP based filtering forced by network service sites where the remote VPN host is installed.