Queue - Local Channel interface and DTMF

Can someone steer me in the right direction when sending a call to a remote agent and that agent must press say * to acknowledged this is a human person answering the call. If the * is not pressed, the call is pullback and the devstate of the local channel that made this call tells the queue the call was not answered and to continue hunting.

We are avoiding the use of AMD and making our agents perform this required task to acknowledge the call is handled.