How do I convert an XmlNodeList into a NodeSet to use within XSLT?

XsltArgumentList arguments = new XsltArgumentList();
XmlNodeList nodelist;
XmlDocument nodesFrament = new XmlDocument();
XmlNode root = nodesFragment.CreateElement("root");
foreach (XmlNode node in nodeList)
{
    root.AppendChild(node);
}
nodesFragment.AppendChild(root);

arguments.AddParam("argumentname", string.Empty, nodesFragment.CreateNavigator().SelectChildren(XPathNodeType.All));