I havent used FrontPage in a while but in the older versions of Frontpage
there was a website setting where you could set the extension of the pages
that were "valid" web  pages... I used to have to do this when I was using
Frontpage at an old company I worked for and needed to view a Cold Fusion
page with a .cfm extension in front page. I think there is also a setting
now to tell it to NOT mess with any non-front page  generated code  in the
page... I think you have to put it in a certain type of front page tag but
once you do it should leave it alone.