如何以编程方式将XmlNode添加到XmlNodeList

I have an XmlNodeList of products whose values are put into a table. Now I want to add a new XmlNode to the list when a certain product is found so that in the same loop the new products is treated the same as the items that are originally in the file. This way the structire of the function does not need to change, just add an extra node that is processed next. But an XmlNode is an abstract class and I cant figure out how to create the new node programatically. Is this possible?I have an XmlNodeList of products whose values