In order to use variables in task sequences we first have insert some. To do that you right click on the desired collection and choose “modifiy collection settings”:

Then you go to the collection variables and click on the yellow star:

Then you will get a window where you can insert a variable name and value like this:

All the different Variables can be found on technet or in the zticonfig.xml file.

Ok, so now we have the variables defined, next we have to do something with the task sequence in order to use them.
First we have to have the mdt-toolkit package configured. In order to create the toolkit package you have follow the “Create Microsoft Deployment Task Sequence” or create the package manually. The files needed in the package is “Zticonfigure.wsf,Zticonfigure.xml,Ztiutility.wsf, ZtiGather.wsf and ZtiGather.xml. In my examples I have create the MDT Toolkit package using the Task Sequence. Okay so now you have the MDT-Toolkit package in place we can now configure the task sequence that ypu want to use the Regional settings.

First I Make sure that the Toolkit package is available for use.

Then I make sure the Gather process is beeing run in order to collect get variables defined in the collection.

Then comes the magic. We will launch the zticonfigure.wsf script. This script takes all the variables collected in the Gather process and writes the values into the unattend.xml file. You can also verify this by looking at the zticonfigure.log file.

Also remember to apply an unattend.xml file to apply operating system task.  Here you can use the default that is created with the mdt toolkit. You have to have like a set of default values for the unattend.xml file and the zticonfigure.wsf will update the values with the collection variables values.
I hope this post will help someone that do not want to waste hours trying to investigate how to make this work.