Is there anyway I can hijack the Site Maintenance feature?

Rather than display a message, when the site is offline, I'd like to redirect it to a different site.

The use case is that, currently, our country specific TLDs redirect to the .com site; when we're developing, say, example.fr, I still want it to redirect to example.com until it's ready for launch. I'm currently using htaccess to handle this but I'd rather do it in a more Drupal fashion than editting mod_rewrite rules.