I am not familiar with borders - I copied and pasted the
line from another document - I'm not sure how the authors
of that document created the line.  I couldn't highlight
the line so I put the mouse arrow over the line until the
4 pointed arrow appeared, did Edit/Copy then Edit/Pasted
it into the footer of the new document.  The line goes all
the way across the footer boundary and is about 3/4 of the
way up.  When I pressed Enter, I could go below the line
and center the cursor but when I used the insert page
number tool bar to insert a page number, it placed the
page number above the line.  I also need to have the page
number in chapter-page format, i.e. 1-1, 1-2, etc. and I
couldn't figure out how to do that.  The reason I am
creating new footers and new documents is I am copying and
pasting each chapter in the original document into its own
separate file so it will be easier to do page numbers
within each chapter.  I had trouble with section breaks
and page numbers getting screwed up within each chapter in
the original document.