How to enable message journaling for an Exchange Server mailbox store by using Visual C++ 6.0

#import "c:\Program Files\Common Files\Microsoft Shared\CDO\cdoex.dll" no_namespace raw_interfaces_only rename("Folder","EXFolder") 
#import "c:\Program Files\Exchsrvr\BIN\cdoexm.dll" no_namespace raw_interfaces_only
#import "c:\Program Files\Common Files\System\ado\msado15.dll" no_namespace raw_interfaces_only  rename("EOF","adoEOF")

int main(void)
{
	::CoInitialize(NULL); 
{
	IMailboxStoreDBPtr pMailboxStoreDB(__uuidof(MailboxStoreDB));
	IDataSource2* pDataSource2 = NULL;
	Fields* pFields = NULL;

	HRESULT hr = pMailboxStoreDB->get_DataSource(&pDataSource2);
	if (SUCCEEDED(hr))
	{
		//TODO Change this to reflect your environment
		hr = pDataSource2->Open(
			L"LDAP://MyServer.Mydomain.com/CN=2nd Mailbox Store,CN=First Storage Group,CN=InformationStore,CN=MyServer,CN=Servers,CN=SITE1,CN=Administrative Groups,CN=MyOrganization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=MyDomain,DC=com",
			NULL, 
			adModeReadWrite, 
			adFailIfNotExists,
			adOpenSource, 
			L"",
			L""); 
		if (SUCCEEDED(hr))
		{
			//pVarFields = pMailboxStoreDB->GetFields();
			hr = pMailboxStoreDB->get_Fields(&pFields);


			if (pFields)
			{
				//Append property
				_bstr_t _bstrName("msExchMessageJournalRecipient");
				
				//TODO Change this to reflect your environment
				_variant_t vFieldValue("CN=MyUser,CN=Users,DC=MyDomain,DC=com"); 

				//Append only if the field is empty
				hr = pFields->Append(
					_bstrName, 
					adBSTR, 
					_bstrName.length(),
					adFldUpdatable, 
					vFieldValue);

				if (SUCCEEDED(hr))
				{
					//Update cache and directory
					hr = pFields->Update();
					hr = pDataSource2->Save();
				} 
				pFields->Release();
			}
		} 
		pDataSource2->Release();
		pDataSource2 = NULL;
	} 
}
	::CoUninitialize();
	return 0;
}