Now that I already explained how to create a basic add-in for the VBA editor of Office using Visual Studio and the .NET Framework, and how to debug it, it’s time to add a more complex user interface:

HOWTO: Adding buttons, commandbars and toolbars to the VBA editor of Office from an add-in with Visual Studio .NET.
http://www.mztools.com/articles/2012/MZ2012015.aspx