using System;

​

public class Program

{

    public static void Main()

    {

        string  str = "Re:_=C8SOB_Poji=9A=9Dovna";

        char    ch, q;

​

        for(int idx=0; idx<str.Length; idx++)

        {

            // Default - interpret as a single character

            q = ' ';

            ch = str[idx];

            if(str[idx]=='=' && idx+2<str.Length)

            {

                // Assume HEX, otherwise catch and use defaults

                try {

                    ch = (char)Convert.ToInt32(str.Substring(idx+1,2),16);

                    idx+=2;

                    q = '"';

                    // "Quote" converted character

                }

                catch {};

            }

​

            // Do something with result

            Console.WriteLine( "{0}{1}{2}", q, ch, q);

        }       

    }

}