Hi Slain very doable but your explanation is a tad lacking.
Best to provide a network diagram to illustrate all the players involved and at which end of the tunnel.
As well providing the config of the MT device behind the main router and the device (mt?) at the other end of the tunnel would be critical.
Can you confirm the speedpass you are able to do port forwarding but not able to set static routes?
Also have a read through this article for some ideas…
http://forum.mikrotik.com/t/mikrotik-wireguard-server-with-road-warrior-clients/148392/1