Thank you Andrew - that was the information I required. Since I have no need for higher order headings in this document, and my template already had Heading 6 onward set up for no numbering, I connected list bullet to Heading 6 and changed my headings to Heading 6 rather than Heading 1.
There is one 'odd' heading in the document that requires a letter as well as the number (7A) so to achieve that I attached Heading 7 to list bullet 4.
I can see that such a setup could be problematic in a large document but for this case it works very well.

Unfortunately this didn't seem to work either Stefan but thank you for the suggestion.

Regards

Murray