Full Name:
How to: Use Managed Code as an Automation Add-In for Excel (C#)

Short Name:
How to: Use Managed Code as an Automation Add-In for Excel (C#)

Type of Entity:
C#

Abstract:
With Automation add-ins for Excel, you can use a public function from your COM library to be called as a cell formula. The following example illustrates how to create a C# add-in for calculating income tax rate in a cell in an Excel worksheet. ComRegisterFunctionAttribute automatically registers the add-in, and no additional tools are required to register the managed code as a COM assembly. For additional information, see Interoperability Overview (C# Programming Guide).

MSDN Source URL:
http://msdn2.microsoft.com/ms173189.aspx