What you will need to do will require some custom configuration and currently there is no step by step guide as i will not have time to write one for you but here is an overview and you can use google and this forum to direct you in the correct direction.
First you must use the locations plugin as explained in the previous post.
Than a great tutorial George1421 wrote up will get you used to injecting custom modules
https://forums.fogproject.org/topic/14278/creating-custom-hostname-default-for-fog-man-reg
I used this to create a custom custom script to attach my devices to specific locations based on IP address, so that way when they register using either quick or manual reg they automatically get assigned to the correct location and thus will pull from the correct server and have the specified hostname i use LOC-SERVICETAG
Then if you done make use of different images or dont want to fill in the manual reg questions all the time you can edit the files and prefil data or take out questions you dont need to answer.
If you spend a few days you can have a super easy to use system like i have. All i need to do is boot an unregistered system into PXE and it will auto assign hostname, location, image and groups and schedule it for image. After registration it reboots and starts imaging. Then i have the AD defaults pre programmed so the device joins the appropriate domain and OU for that location.
Hope this helps get you going the software is really great but does take some time to get setup correctly where you can image with ease.