VPN over NAT

I need some advice.

A friend lives in Belgium and would like to use VPN to to connect to my network and get a US IP address. I’d like to make it easy on him, so my idea is to give him a DD-WRT wifi router that he can plug into his existing router, then connect to the DD-WRT when he needs VPN (for a roku box, etc…). Is this possible??

Thanks,
Eric

Very easy.
http://wiki.mikrotik.com/wiki/Manual:Interface/PPTP