For the most part you can pretty much do anything in VBA that you can do with the UI, but not with the Office 2007 Ribbon, instead of providing developers with a way to customize it Microsoft instead used XML markup language as a basis for customization.

I'm not going into details here about how to customize the ribbon, but I will point you in the right direction:

MSN Article on how to customize:
http://msdn.microsoft.com/en-us/library/aa338202.aspx
Check out the UI Customization in Microsoft Access section.

Purchase a tool that will do it for you:
http://pschmid.net/office2007/ribboncustomizer/index.php

Do it yourself approach:
http://www.access-freak.com/tutorials.html#Tutorial05

I hope these links helps you in your quest to customize the ribbon!

Keywords:
Customize Office 2007 Ribbon with VBA
Autohide ribbon with VBA
Minimize ribbon with VBA
Hide Office Ribbon VBA