re-route traffic of hotspot to VPN

Hello,

I’m currently using Mikrotik as a primary router for DHCP Server and Hotspot Server. The internet connection is PPPoE from the Mikrotik to ISP (FTTx). I setup another VPN connection (PPTP) on Mikrotik to outside VPN server on the internet. I want to re-route all traffic from Hotspot Users to goes on VPN connection (PPTP). How can I do that?