using System;

using System.Web;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(UnicodeConvertChar('ז'));

        Console.WriteLine(HttpUtility.HtmlDecode(UnicodeConvertChar('ז')));

    }

    private static string UnicodeConvertChar(char input)

    {

        if (input > 159)

        {

            return "&#" + ((int)input).ToString() + ";";

        }

        else

        {

            return input.ToString();

        }

    }

}

​