Bittorent client over VPN

Hi there, I would like to use a BitTorent client on my readynas 314 but have it going over VPN (probably to online VPN service provider, i.e. I want all the VPN client traffic to go outbound/inbound  to a VPN host somewhere on the internet but don't want to use a site to site service with my router.

 

Please let me know the simplest way to do this.

 

Thank you.