Sandi, could you clarify the requirement for underlining -- is the underlining intended to indicate changed text? If so, have you considered using FM's built-in change bar capability? Although the underlining itself isn't in red, the change bar indicators in the margins are very, very useful and might perhaps be workable.
Also, pls let us know which specific version of FM you're using (from Help > About, including the "pxxx" numbers).