<code lang="Generic">
using System.Xml;
using System.Xml.XPath;        

        private string m_xml_path;
        private string m_xml_filename;        
        
        public string FilePath
        {
            get { return m_xml_path; }
            set { m_xml_path = value; }
        }

        public string FileName
        {
            get { return m_xml_filename; }
            set { m_xml_filename = value; }
        }

        private XPathNavigator CreateNavigator(string path, string filename)
        {
            XPathDocument doc = new XPathDocument(path + filename);                       
            return doc.CreateNavigator();
        }
                
        public string GetXMLString(string xpath)
        {
            string xmlString = null;
            try
            {
                XPathNavigator nav = CreateNavigator(m_xml_path, m_xml_filename);
                XPathNodeIterator iter = nav.Select(xpath);
                iter.MoveNext();
                xmlString = iter.Current.Value;
                iter = null;
                nav = null;
            }
            catch (XPathException xe)
            {
                throw new XPathException(xe.Message);
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }            
            return xmlString;
        }
</code>