Read this and the simple solution is to create a third vlan for the third subnet.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
Read this and the simple solution is to create a third vlan for the third subnet.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1