Copying one xml docu into another xml doucment using c# code

public void GenerateFooterTablixcode(XmlDocument sourcedoc,XmlElement reportItems)

{
   XmlDocument copydoc = new XmlDocument();
     copydoc.Load(@"C:\Users\Documents\Visual Studio 2010\Projects\Report Project1\RdlGeneration\XMLFile1.rdl");

     ---code to copy the copydoc xml doucment object to reportItems xmlElement of XmlDocument.
      ---

       --

       ---

}