public static void Main()
string data = "%B3%F3%C7%F9";
byte[] bData = new byte[data.Length / 3];
for (int i = 0; i < data.Length; i += 3)
bData[pos] = Convert.ToByte(data.Substring(i + 1, 2), 16);
data = System.Text.Encoding.GetEncoding("euc-kr").GetString(bData);