VSTO
http://blogs.msdn.com/mshneer/archive/2006/01/05/deployment-articles.aspx
http://blogs.msdn.com/vsto2/archive/2005/10/11/479825.aspx
http://msdn2.microsoft.com/en-us/library/aa537173(office.11).aspx
http://msdn2.microsoft.com/en-us/library/aa537179(office.11).aspx
hope this helps...
:-S