Dual Wan Failover and PPTP Server

Hi! im going to use a mikrotik 951 in an office with 2 wan connections but also need the mikrotik to act as a vpn concentrator (PPTP)
Its posible to do it for both wan? I ll have only one wan active with the pptp server but in case this wan goes down i d like to have the concentrator working on the other wan (active)

Thanks

you need to mark the connection that come from outside and then assign a route to them so when they want to leave the router they go from the same way that they got in.

https://mum.mikrotik.com/presentations/US12/tomas.pdf

Many thanks! I ll try it and comment!