RT-AC66U - VPN service to only one device?

Hi everyone.

I have an RT-AC66U router running on the latest asus firmware.

I was wondering if there is a way that I could connect a VPN service through the router and then have that VPN service only applied to one specific device (not all wifi/lan devices).

If there is any step by step instructions that someone can point me towards to, that would be appreciated.

Cheers!