Video: Developing an Excel Automation Add-in
As a follow up to the Creating managed Excel UDFs video, here is a video that explains how to build UDFs using Excel Automation add-ins. In addition to a solid demo, this video explains the differences between an UDF built with an Automation Addin and one built as an XLL.
If you are looking to extend Excel with custom functions, you want to watch this video.
This video was captured in Visual Studio 2010 with Add-in Express for Office and .NET.