Casters in party, How to get it to work?

So I successfully RaFd my first 85s today, and im ready to start a few more. however, the ones i want to start are a druid(tank) and warlock. How do i get my warlock to turn towards my druids target? When i leveled my rogue and warrior, my rogue walked to my warriors target and attacked it with no problems at all. how do i do this for my Lock?

set up a interact with target key and I will make the caster stop walking to your target and start its cast, as far as turning you will have to set up a left and right turn key if you cant keep the tank inline with the caster, I would drive with the caster and make the druid tank iwt as when you hit that key the druid will walk to the target and engage it and the warlock your still controlling will be where you can move it and cast,