Message Decrypter

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            int count = int.Parse(Console.ReadLine());
            for (int i = 1; i <= count; i++)
            {
                string result = "";
                string message = Console.ReadLine();
                string[] tokens = message.Split(": ").ToArray();
                string tag = tokens[0];
                string numbers = tokens[1];
                Regex regex = new Regex(@"^(\$|%)[A-Z][a-z]+\1: \[\d+\]\|\[\d+\]\|\[\d+\]\|$");
                bool match = regex.IsMatch(message);
                if (match == false)
                {
                    result = "Valid message not found!";
                    Console.WriteLine(result);
                }
                else
                {
                    Regex groups = new Regex(@"^(\$|%)[A-Z][a-z]+\1: \[(\d+)\]\|\[(\d+)\]\|\[(\d+)\]\|$");
                    Match matching = groups.Match(message);
                    string firstNumGroup = matching.Groups[2].Value;
                    string secondNumGroup = matching.Groups[3].Value;
                    string thirdNumGroup = matching.Groups[4].Value;
                    int firstNumber = int.Parse(firstNumGroup);
                    int secondNumber = int.Parse(secondNumGroup);
                    int thirdNumber = int.Parse(thirdNumGroup);
                    string oldChar1 = firstNumber.ToString();
                    string oldChar2 = secondNumber.ToString();
                    string oldChar3 = thirdNumber.ToString();
                    char newChar = (char)firstNumber;
                    string newChar1 = newChar.ToString();
                    char new2Char = (char)secondNumber;
                    string new2Char2 = new2Char.ToString();
                    char new3Char = (char)thirdNumber;
                    string new3Char3 = new3Char.ToString();
                    numbers = numbers.Replace(oldChar1, newChar1);
                    numbers = numbers.Replace(oldChar2, new2Char2);
                    numbers = numbers.Replace(oldChar3, new3Char3);
                    string decryptedMsg = newChar1 + new2Char2 + new3Char3;
                    string newTag = tag.Remove(0, 1);
                    newTag = newTag.Remove(newTag.Length - 1, 1);
                    Console.WriteLine($"{newTag}: {decryptedMsg}");
                }
            }
        }
    }
}