在C＃中读取CSV时忽略列的最佳方法是什么？

Question

所以我读了一个大的CSV文件，它可能看起来像

"Intelligent Mail barcode","Sack and Pa","Opt. Endorsement Line","Label ","NAME","COMPANY","DELADDR","CITY","ST","ZIP"
"xxxxxxxxxxxxxxxxxxxxxxxxx","T1  P1","******AUTO**MIXED AADC 403","xxxx","xxxxxxxx","xxxxxxxxxxxxxxxx","xxxxxxxx","xxxxx","xxxx","xxxxx"
"xxxxxxxxxxxxxxxxxxxxxxxxx","T1  P1","******AUTO**MIXED AADC 403","xxxx","xxxxxxxxxx","xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","xxxxxx","xxxxx","xx","xxxxx"

我想在这种情况下删除前4列。所以智能邮件，Sack和Pa，选择。支持，Label1将被忽略，与它们相关的数据也将被忽略或空白。

所以输出就像

"NAME","COMPANY","DELADDR","CITY","ST","ZIP"
"xxxxxxxx","xxxxxxxxxxxxxxxx","xxxxxxxx","xxxxx","xxxx","xxxxx"
"xxxxxxxxxx","xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","xxxxxx","xxxxx","xx","xxxxx"

我怎样才能做到这一点？寻找最简单的方法。

以下是我目前读取CSV的方式：

        using (StreamReader reader = new StreamReader(fileSaveLocation))
        {
            string line;
            header = reader.ReadLine();

            while ((line = reader.ReadLine()) != null)
            {
                sb.Append(line);
                sb.Append(Environment.NewLine);
            }
        }