Filename of referenced doc

The FullDocumentName seems to be the filename. Here's an example

       CComPtr<ComponentOccurrence> pThisCompOcc  ;

       hRes = pOccurrencesList->get_Item(1, &pThisCompOcc);

    if (FAILED(hRes) || (pThisCompOcc == nullptr)){

        ShowCOMError(hRes,L"GetComponentOccurrenceByName, get_Item failed "); 

        return ;

    }

    // Now find out the part which this is a view of...

    CComPtr<DocumentDescriptor> pDocDesc  ;

    pThisCompOcc->get_ReferencedDocumentDescriptor (&pDocDesc) ;

    CComBSTR bstrFullDocName ;

    pDocDesc->get_FullDocumentName (&bstrFullDocName) ;

    WalertBoxW (L"Referenced doc = %s",bstrFullDocName) ;