Wordpress Mapping Domain. Plug in and go. Domain Mapping Using a Plugin NO LONGER RECOMMENDED For posterity Im including the original method which utilizes the plugin.
Go to wordpress admin page and take a look at Settings - General. Plug in and go. It means your wordpress installation dynamic enoungh to accomadate both domain address WordPress Admin - Settings - General.
Now that you have your new subsite setup you need to map your live domain to it.
That is put it above the line that says. This lightweight plugin maps domains to specific URIs in your blog or website. For landingpages as you want. But with the WordPress MU Domain Mapping plugin you have to manually install it.
