The first step to use a COM object is to find it. COM objects are registered in the system registry and are associated with an unique Class Identifier, known as CLSID. A CLSID may also be associated with a string known as Programmatic Identifier or ProgID. This last one is the easiest way to reference a COM object. E.g., the ProgID for Microsoft© Word© is ``Word.Application''.
If one do not know in advance what is the CLSID or the ProgID of the object of interest, them it's possible to use tools like OleView to find the object, although the best place to find it is in the object's documentation.