Develop VSTO-based COM add-ins for MS Office using Delphi Prism exactly in the same way as you do it using VB.NET and C#. The VSTO Support for Delphi Prism Wizard gives you an opportunity to benefit from all advanced features of VSTO, including its programming and deployment models, Ribbon designer, MSI-based setup projects, Outlook form regions and Office Task panes. It supports Excel, Outlook, Word, PowerPoint, Project, Visio and InfoPath.

This is a free sample add-in (ready to install and use) that adds a number of useful features to Microsoft Excel. The add-in is based on the innovative Add-in Express technology and gives you an example of developing Excel add-ins, creating custom toolbars and controls and accessing Excel objects. The add-in contains a full source code in VB, C# and supports Excel 2003 and Excel 2007. It works in VSTO 2005 SE and VSTO 2008 (VB.NET, C#).