In your example, there is no specific location that is easily accessed. "Enter case references" is a prompt for your FillIn field.

You could, instead, use an ASK field with a related REF field to display the information.
The ASK field creates a hidden named bookmark which is a location in the file.

See the ASK and FILLIN field tutorial. Tutorials

Using Fields in Microsoft Word

If your REF field or the inserted information is the first thing in the document and there is no Title property, the first line of your document will be the default name for the document.

Note that anything else you do (other than putting your case reference at the beginning)is going to require macros. The trick then is to get users to allow the macros to run.