Re: How do I insert a payment button into a word document?
You would have to use a text or hyperlink.
You can build your own Button Text Links from scratch or take advantage of the Online Button Creator within your PayPal Account. After generating the button code online, select the "Email" tab to view the Text Link Code. Note, the "Email" tab will not be available if have included dropdown selections or text boxes in your item button code. This is because you cannot include dropdown selections or text boxes in a Text or Hyperlink.
If you want to see a few manually coded text or hyperlink examples, check out this page.