[c#] Loading custom configuration files

The config file is just an XML file, you can open it by:

private static XmlDocument loadConfigDocument()
{
    XmlDocument doc = null;
    try
    {
        doc = new XmlDocument();
        doc.Load(getConfigFilePath());
        return doc;
    }
    catch (System.IO.FileNotFoundException e)
    {
        throw new Exception("No configuration file found.", e);
    }
    catch (Exception ex)
    {
        return null;
    }
}

and later retrieving values by:

    // retrieve appSettings node

    XmlNode node =  doc.SelectSingleNode("//appSettings");