Microsoft has released a great guide for How to use Group Policy to deploy and configure an installation of Microsoft Office 2010. The guide can be found here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=66a6848c-6c28-4b61-9c12-a8cad4b380a4
Inside this document is also a great link to another great document. They have created a document that helps you find the right policy setting for a specific UI setting. Found here: http://go.microsoft.com/fwlink/?LinkId=106122
I suggest reading this if you are in the middle of an Office deployment project. It really covers every aspect of the deployment process.
This guide also states that it is not supported to deploy office with Group policy software installation. There has been some un-clarity about that subject. But here it is, black on white.