MSDN OLE DB Sample Provider entry point

Hello everyone,


I have built MSDN OLE DB Sample Provider and successfully built/debug it using Microsoft Excel as client. I have found that in DllGetClassObject (classfac.cpp), the class SampProv is initialized as the 1st coclass, then DataSource object will be created in QueryInterface.

http://msdn2.microsoft.com/en-us/library/ms715011.aspx

The entry point of a COM server (like this Sample OLE DB Provider) is creating a coclass through DllGetClassObject. My question is, how did Microsoft Excel find the entry point coclass of the OLE DB Provider is SampProv coclass?

I have this question because Excel is a client with no knowledge about any specific application defined CLSID, like SampProv, how could it be aware of this ID (i.e. Excel knows nothing about 3rd party application's specific name of entry point coclass)? In Windows registry, I can not find any related information indicating that SampProv should be the entry point coclass either.


thanks in advance,
George