Microsoft Visual Studio 2015 Unleashed, Third Edition

Creating an Office Document Extension

You can customize Office documents in various ways. You can host controls in a document, create actions panes specific to a document, and store data within a document.

A document-level project is created using the same process we used for add-ins. This time, however, you select an Excel Workbook or Word Document project type. These project types use designers that represent the look and feel of an Excel workbook or a Word document.