Thanks Africo,
I spent some time this morning testing this the way you said, and it's working perfectly.
To clarify for others, you are editing the Email Monitor workflow. In the ProcessMessage model, you need to add the "Get Incident Service Queue by Name" component before the "Create Incident" component.
In the "Get Incident Service Queue by Name" component, you can select the input, select constant value, and type the name of the queue you want to send to.
After that (and after you have linked them), on the "Create Incident" component, open up the mapping definition, and on that screen there is the CurrentlyAssignedQueue Mapping that is in Africo's screenshot. You create the mapping, and connect the ServiceQueueObject.QueueName (that comes from the Get Inc. Queue by Name" component) to the IncidentTicket.CurrentlyAssignedQueue.QueueName.