Set a default ItemId if the Itemid missing in the URL?

My problem is quite simple...

I want Joomla to use a default ItemId when it´s missing in a URL.

The base of the problem is that i want to show articles in a different view then it shows i the "home" menu.

When I disable some modules from being used with the hole site they vanish when I want to read an article that's originate from the "frontpage" because the "frontpage" missing the Itemit as default in the URL.

So I want to some way tell Joomla that if itemid missing to use Itemid=99 as default, then I can build the modules for Itemid=99 direct in the database.

Regards,
Fredrik Gidensköld