USE MySQLDB;
GO
DECLARE @myDoc XML;
SET @myDoc = '<QBXML>
<QBXMLMsgsRq onError="stopOnError">
</QBXMLMsgsRq>
</QBXML>';
SET @myDoc.modify('
insert
-- instead of inserting string here.. I would like to insert here the query I made above
into (/QBXML/QBXMLMsgsRq)[1]');
SELECT @myDoc;