Extract detail from barcode on bollettini prefilled (Italy)

namespace PSC
{
    public class Bollettini
    {
        public bool getCode(string strCode)
        {
            bool rtn = true;

            if (strCode.Length != 50)
            {
                return false;
            }

            int first = Convert.ToInt16(strCode.Substring(0, 2));
            Bollettino = strCode.Substring(2, first);

            int second = Convert.ToInt16(strCode.Substring(first + 2, 2));
            Contocorrente = strCode.Substring(first + 4, second);

            int third = Convert.ToInt16(strCode.Substring(first + second + 4, 2));
            string tmp = strCode.Substring(first + second + 6, third);
            Importo = Convert.ToDecimal(tmp) / 100;

            int fouth = Convert.ToInt16(strCode.Substring(first + second + third + 6, 1));
            Codice = strCode.Substring(first + second + third + 7, fouth);

            if (Codice != "896")
            {
                rtn = false;
            }

            return rtn;
        }
    }
}