RichEdit to RTF - margins

I'm having a problem using RichEdit.lines.SavetoFile to make an RTF file to
be read by MS Word.  It makes the file OK, but when the file is brought un
in Word, Word has set the left and right margins to 1.25 inch, leaving only
6 inches across, whereas the file needs 8 inches across to look right.
Setting the default margins to 0.25 inch in Word doesn't help.

I'm wondering if there is a way to set the margins in the RTF file. Even if
there isn't a way to do it before the RTF file is written, it seems that
there should be a way to modify the RTF file to set the margins at 0.25
inch.  I don't know the RTF format, so how can you set the margins in the
RTF file?