is it possible to make your own syntax in c# or something equivalent or make my own string format to wok with...?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Mail;

namespace methods
{
    class Program
    {
        static void Main(string[] args)
        {
            ////string opr = Console.Read(string.Format("{0}: {1},{2}",op_nm,op1,op2));
            //string a;
            //a="add: 2,3";

            ////if(a == Console.ReadLine().ToString(string.Format("{0}: {1},{2}",));
            //do{

            //}while(repi == true);
            Console.WriteLine("Write function you desire.");
            string op_syn;
            op_syn = Console.ReadLine();
            char[] choi = {':'};
            string[] distri_syn;
            distri_syn = op_syn.Split(choi);
            foreach (string word in distri_syn)
            {
                Console.WriteLine("{0}",word);

            }
            for (int i = 0; i < distri_syn.Length; i++ )
            {
                if(distri_syn[0]=="add" & distri_syn[1]==": " /*& distri_syn[2]==""*/ & distri_syn[3] == "," )
                {


                }
            }
                //Console.WriteLine("{} ");
                Console.Read();
        }
        public static void add(int)
        {
            long op1, op2;

        }
    }
}