Current plugins don't support it, if you have specific requirements email us to [Only registered and activated users can see links. ]
Use anonymous proxy instead of transparent, transparent proxy provides real ip to server.
Refer to mc2guide for proxy setup -> [Only registered and activated users can see links. ]
If you are using VPN, there is no need to setup anything in cmc2, just make sure vpn is connected properly in your system and it changes your ip accordingly.