Hi Jason,
To accomplish what you are trying to accomplish you'll need to define a customer group for each support location. As you define each customer group you'll see a default location drop down that lists all of your support rep locations. Once you've defined all of the customer groups you need to set the customer's support location, you'll select the primary group that indicates the support location on each customer record. This can also be done at a company level, but if you're using AD integration the company value comes from AD so you'll probably have to do it on a customer by customer basis. Once this is done, a ticket submitted via your EUD will first look to assign the new ticket to a skilled rep for the category selected at the support location that matches the support location associated with the customer's primary group. If no skilled support rep for the category is available at that location the default assignee selections you made for your EUD will be applied. Hope this helps. If you run into anything you have questions about as you look in to this further, my direct number is (360) 397-1041 or you can just call or main support line and speak with one of our support reps.
Darren