title: Issue renaming two columns in a CSV file instead of one
body: <p>I need to be able to rename the column in a spreadsheet from 'idn_prod' to 'idn_prod1', but there are two columns with this name.</p>
  
  <p>I have tried implementing code from similar posts, but I've only been able to update both columns. Below you'll find the code I have that just renames both columns.</p>
  
  <pre><code>//locate and edit column in csv
  string file1 = @"C:\Users\username\Documents\AppDevProjects\import.csv";
  string[] lines = System.IO.File.ReadAllLines(file1);
  
  System.IO.StreamWriter sw = new System.IO.StreamWriter(file1);
  foreach(string s in lines)
  {
      sw.WriteLine(s.Replace("idn_prod", "idn_prod1"));
  }
  </code></pre>
  
  <p>I expect only the 2nd column to be renamed, but the actual output is that both are renamed.
  Here are the first couple rows of the CSV:
  <a href="https://i.stack.imgur.com/P0NuQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/P0NuQ.png" alt="enter image description here"></a></p>