as long as your healer has the mob targeted it should be the exact same way as any other setup, weather or not it's a tank or healer at the head...
Just target with your main and make him the focus and make this macro for the slaves:
/cast [target=focustarget] spell name


And i would use Healbot to heal with since you can just click it and it heals your group, those 2 things together should make it pretty easy