Selecting Xml Nodes in MSXML 3 via XPath

Apparently, you need to set the SelectionLanguage property of a JavaScript XML Document object to XPath so you can select nodes via XPath.

var xmldoc = new ActiveXObject("Microsoft.XMLDOM");
// or var xmldoc = new ActiveXObject('Msxml2.DOMDocument.3.0');
xmldoc.async = "false";
xmldoc.loadXML(xmlData);
xmldoc.setProperty("SelectionLanguage", "XPath");

After which you can use XPath to select nodes. This is inevitable for MSXML 3.