Some thoughts born of deep ignorance of newsletter templates....
I'm pretty sure you can't get Word to generate another page.
You could add another page manually, but then you would have to duplicate
the formatting/layout yourself. Copy and Paste might or might not work.
I think probably what is most worth your time would be to continue the
newsletter in a new/second document based on the same template, finish the
newsletter off, then futz about with ways to combine them. Make copies of
both before you start messing with them.
Some options:
Use Insert | File to insert the second newsletter into the first and see if
Word fixes the page numbering automatically. (if Word doesn't fix the
numbers, but Insert File works fine otherwise, we might be able to help)
OR
In the second newsletter, View | Header/Footer and use Format Page Number (#
with hand) to start at 9. If you are printing, no problem. If you mean to
send them electronically, I would send them as PDFs rather than Word
documents anyhow, and after PDFing both, would google for a freeware utility
Combine PDFs to paste them together, assuming you don't have other PDF
creation software.