I would strongly urge you to consider using a
Template or Header
AutoText/ Building Block for this. IMO, it is much easier to fine-tune.
This recommendation may speak to my (lack of) vba coding skills. However, I have long found use of built-in capabilities of Word to be superior to coding when both can produce the same result. It may well be that you need to do it as part of a longer procedure. However, creating a document through code rather than using a template seems like an exercise in frustration.