Looks up a CLSID in the registry, given a ProgID. 
HRESULT CLSIDFromProgID(
  LPCOLESTR lpszProgID,  //Pointer to the ProgID
  LPCLSID pclsid         //Pointer to the CLSID
);

  
Return Values

  

   
    S_OK 
   
   

    The CLSID was retrieved successfully. 
   

   
    CO_E_CLASSSTRING 
   
   

    The registered CLSID for the ProgID is invalid. 
   

   
    REGDB_E_WRITEREGDB 
   
   

    An error occurred writing the CLSID to the registry. See "Remarks" below.