One significant part of developers (including myself) are doing some kind of automation of Microsoft Office that was already treated by Mike Gold. So I will concentrate on opposing side of problem, how to use managed assembly from MS Office or VB scr ipt. It is a good idea to check your .NET fr a mework SDK Documentation, especially Interoperating with Unmanaged Code. For a start we will first check managed side of story. To expose managed types, properties, fields, or events to COM they must be public. Types can t be abstract and they must have default constructor. It s recommendable to define interface explicitly but it is not necessary, tools provided with .NET Platform are capable of creating one for you.-One significant part of developers (including myself) are doing some kind of automation of Microsoft Office that was already treated by Mike Gold. So I will concentrate on opposing side of problem, how to use managed assembly from MS Office or VB scr ipt. It　is a good idea to check your .NET fr a mework SDK Documentation, especially Interoperating with Unmanaged Code. For a start we will first check managed side of story. To expose managed types, properties, fields, or events to COM they must be public. Types can t be abstract and they must have default constructor. It s recommendable to define interface explicitly but it is not necessary, tools provided with .NET Platform are capable of creating one for you.