using System;

using System.Xml;

using System.Xml.Linq;

using System.Xml.XPath;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        string response = @"<response location='location1'>

            <meas name='mt1'>14</meas>

            <meas name='mt2'>23</meas>

            <meas name='mt3'>65</meas>

            <meas name='mt4'>31</meas>

            <meas name='mt6'>32</meas>

        </response>";

        string[] return_values = new string[6];

        string[] names = new string[6] { "mt1", "mt2", "mt3", "mt4", "mt5", "mt6" };

        XmlDocument xml = new XmlDocument();

        xml.LoadXml(response);

        for (int i = 0; i < return_values.Count(); i++)

        {

            var node = xml.DocumentElement

                .ChildNodes

                .Cast<XmlNode>()

                .FirstOrDefault(x => x.Attributes["name"].Value == names[i]);

            return_values[i] = node?.InnerText.ToString();

        }

        //return_values[0] = xml.SelectSingleNode("//meas[@name=\"mt1\"]").InnerText.ToString();

        //return_values[1] = xml.SelectNodes("//meas[@name=\"mt2\"]")[0].InnerText.ToString();

        //return_values[2] = xml.SelectNodes("//meas[@name=\"mt3\"]")[0].InnerText.ToString();

        //return_values[3] = xml.SelectNodes("//meas[@name=\"mt4\"]")[0].InnerText.ToString();

        //return_values[4] = xml.SelectNodes("//meas[@name=\"mt5\"]")[0]?.InnerText.ToString();

        //return_values[5] = xml.SelectNodes("//meas[@name=\"mt6\"]")[0].InnerText.ToString();

        Console.WriteLine(String.Join(", ", return_values));

    }

}