The integration of Office into Microsoft's .NET initiative is still something to wait for; that is, Office programming is still done in VBA. For programmers who are already familiar with .NET, there is, however, Visual Studio Tools for Office. In combination with Visual Studio .NET 2003, you can develop Word and Excel programs in which the relevant programming languages are VB.NET and C#. (Other Office components are not yet supported.)
Visual Studio Tools for Office is not seen as an integral component of Office 2003, but is offered separately. Further information is available at the following address:
http://msdn.microsoft.com/vstudio/office/officetools.aspx