I see you commented below that you used OpenVPN for implementing this. I tried using a self-hosted Squid proxy with the Spectrum website, but was unsuccessful at getting it to work. I also tried routing the traffic over SOCKS5 (using ssh -D) and it still didn't work. This was a while ago, but I recall that the website was using Flash. I'm just assuming that the website was using Flash to do some local network checking outside of the tunneled traffic and that's why it didn't work, but I'm uncertain if that makes sense. Sounds like I should have tried a full traffic solution like a VPN...