Here is a temporary link to a template and sample document that do this. I attempted to explain the process in the template. To use it, you would put the template in your Word
Startup Folder. There are no macros in these files.
The Frame is set in a paragraph style. Then the Sequence field is inserted in the frame. Then this is saved as an AutoText entry so that both the frame and the number can be inserted as a whole. As set up, the frame will handle numbers up to 9999.
Template with Marginal Paragraph Numbering
This is a zip file with both the template and a sample document.
00 deleteme 2.png
The way I have this set up, the text in the frame is right-justified. It is also formatted for "keep with next" so that the number doesn't end up on a different page than then text.
To really use this, you are going to need to understand
SEQuence Fields and
frames.
Also, if you insert the AutoText entry more than once for a paragraph, you will get overlapping frames and a skipped number. You won't see the underlying frame that would be using a number.
