I have some users who insist on enabling “Use Microsoft Word 2003 To Edit Email Messages”. The Sign/Encrypt icons don’t appear in the compose window along with the decrypt icon for the reading view. Is there a registry hack or something I can do to get pgp4win to work with Outlook 2003 setup this way?
IIRC from what I heard from the GPGol developers
it is probably not entirely imposible to
hack in the GPG support also into the
Word editor.
However, it takes free development time
which the team is short of. You may want
to buy time 
Alternatively, ask on the gnupg-devel list
for some poiinters into the code and the
TODOs for a Word integration.
If the devlopers have some good ideas how
to approach the problem, they will happily
share them if you volunteer to work on it 