Frontpage's dynamic features are only going to work on a server with Frontpage extensions anyway. If you're just using it to design pages then all those nifty "features" really are a waste of time. Do you have access to PHP or ASP on the server your site is hosted on? If so you could easily accomplish this with server side includes. Without a pre-processor you can resort to javascript includes but I think they are more trouble than they are worth.

To find out if you have php. Open notepad and put <?php phpinfo() ?> on a single line and save the file as phpinfo.php (very important, not .html). Then upload the file to your space and try to load it. If you get a page with a lot of technical info on it your're good to go.