Thanks for your helpful reply, Graham.

I will study this in more detail this morning, but the main thing that strikes me is that you (and many other references I have looked at!) are suggesting running the macro on opening the document. This is the problem...

The user will first create a new document, such as the agenda for a meeting and, when it is complete, then run the macro to bring up the user form. This form has some simple questions about the type of document, the body for which it has been written and the date of the document. From these replies it constructs the rather abstruse document name that the filing system requires for archiving - eg:

VHT Mtg 04 Agenda 17 Apr 2021.pdf

The filing system was not my idea! But, as you can see, there is plenty of opportunity to mess up the name structure, especially by a not-very-computer-literate operator, which is why I devised the form.

So how can I prevent the macro from running immediately, but delay it until the user has written the document and wants to file it?