如何从csv文件中读取数据并将该数据写入新csv文件中的某些行

我想在一个文件中读取，并在另一个文件中写入某些列

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace ConsoleApplication2
{
class Program
{
    static void Main(string[] args)
    {

        try
        {
            using (StreamWriter sw = new StreamWriter("AEJoinerDataTemplate.csv"))
            // using streamwriter to write to a text file
            using (StreamReader sr = new StreamReader("AutoEnrolment.csv"))
            // using streamreader to read a text file 
            {
                while ((txtline = sr.ReadLine()) != null)
                {