Adding to IE, or Office App Toolbar

Just curious as to whether anyone has sample code on creating apps which tie into the title bar of Internet Explorer, Office, etc...

Example: Posting your own shortcut on the IE Standard Button bar to an app you have written - or creating a shortcut on the Word Bar to an app which would take the current document and do a mass mailing...

Is this as simple as creating an object of IE and adding to the toolbar...

Thanks in Advance,

Rob Scott