Keyboard command for focusing on menu bar

In Windows, pressing the ALT key focuses on the top menu bar, allowing you to type in a letter that corresponds to a particular menu. Hitting that letter opens that menu and gives you more letters to push to execute certain menu items.

I recently discovered that it is possible to create Keyboard shortcuts for applications through the System Preferences. However, for the particular command that I was mapping, I need to be able to choose between two different items (a menu item that extends horizontally from the menu).

Is there a way to use the keyboard to move between File, Edit, Window, etc so that I can save some mouse-clicks?

Thanks!