Custom link sub nav

I am using the Custom link widget to create a menu with custom links.
The first level works perfectly.

I need to add sub custom link pages to some of the first level menu headings.
The sub nav links are not pages or posts on the website, they are external.

Is there a way to add sub nav custom links using the custom menu widget?

Thanks web Donkey. I didn’t realize that you could drag and drop the custom links into the positions required. Luckily I found a tut on creating custom sub navigations in wordpress 3.

Use the custom menu feature in Wordpress 3.0 and you can easily specify custom links and sub-menu structure.