[Exim] Working with Outlook 98

Outlook 98 seems to only display one entry of the 'From:' field.

So, If I forward a received e-mail from one of my machines to the
other, my own e-mail address appears in the 'From' line and is the only
one listed by Outlook.

Does anyone know what kind of rewriting rule I should apply for this to
work ?
I tried this without success :
$localpart@$local_domain*,* $2,$local_part@$local_domain$1 f

Thanks.