Thanks for the suggestion. That won't solve the problem as Word still won't export any part of the page that extends beyond the printer's A4 printing zone.
For now I think the solution may be to look into setting up a generic virtual printer with 0 margins on all sides, if such as thing is possible. However, as that's not specifically an Adobe matter, I'll pursue that elsewhere.
Thanks again. I'll keep my original question open in case there is an Adobe solution.