I won’t go in to how you deploy custom templates in Microsoft Office, but there is one important thing you need to do if deploying custom Microsoft Office templates in any other language than English.
When deploying a custom template, you need to create an XML file which loads the actual templates when the users starts an Office application.
The problem with this is, that if you use the template for the XML provided on TechNet with a, for example, Swedish installation of Office, it will not work.
The reason for this is that there is that the language is specified at the top of the XML file. You will need to change that to your corresponding Office installation language, otherwise, no templates will be loaded when the user starts an Office application. In my case, my installation was Swedish, so I changed from 1033 to 1053.
Here is a list of all language codes:
Now that you know this, you can read about how you can create custom templates for Office on TechNet 🙂