using System;

using System.Collections.Generic;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        var map = new Dictionary<string, object>()

        {

            { "Param1", true },

            { "Param2", "\"False\"" },

            { "Param3", 123 },

            { "Param4", "\"1234\"" },

        };

        var script = " I have Param1 and Param2 and Param3 and Param4 ";

        MatchCollection matches = Regex.Matches(script, "Param\\d+");

        foreach (Match match in matches)

        {

            object val = map[match.Value];

            script = script.Replace(match.Value, val is bool ? val.ToString().ToLower() : val.ToString());

        }

        Console.WriteLine(script);

    }

}

​