calling function

how can I call the  put_ConnectionString correctly?

when I do the following I got compile error
                           BSTR bstr = "aaa";
		hr.put_ConnectionString(bstr);


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HRESULT CEPGLibApp::LoadXMLData(LPCTSTR tszXMLFileName)
{
	HRESULT hr = S_OK;

	CComPtr<ISQLXMLBulkLoad> pIXMLBulkLoad;
	hr = CoCreateInstance(CLSID_SQLXMLBulkLoad3, NULL,
CLSCTX_INPROC_SERVER, IID_ISQLXMLBulkLoad, (void **)&pIXMLBulkLoad);

	if (SUCCEEDED(hr)) {
                           BSTR bstr = "aaa";
		hr.put_ConnectionString(bstr);
	}

	if (SUCCEEDED(hr)) {
	}

	if (SUCCEEDED(hr)) {
	}

	return hr;
}

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    ISQLXMLBulkLoad : public IDispatch
    {
    public:
        virtual /* [helpstring][id][propget] */ HRESULT
STDMETHODCALLTYPE get_ConnectionString( 
            /* [retval][out] */ BSTR *pbstrConnectionString) = 0;
        
        virtual /* [helpstring][id][propput] */ HRESULT
STDMETHODCALLTYPE put_ConnectionString( 
            /* [in] */ BSTR bstrConnectionString) = 0;
        

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typedef /* [wire_marshal] */ OLECHAR *BSTR;

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typedef WCHAR OLECHAR;

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