While it's simple to take away functionality from the interface (hide standard menus and toolbars), Microsoft Office contains hundreds of keyboard shortcuts, including keyboard shortcuts that exist for backward compatibility with earlier versions of Windows. For example, longtime users of Microsoft Excel may remember that Shift+F12 will save their document and Ctrl+Insert will copy a cell or object. Your best defense will be to use any events available in Microsoft Excel first, and then look for the other options available to users.