title: replacing line in txt file AFTER specific line
body: <p>demo file below. in group [two] i want to toggle 'enable group' between 0 &amp; 1 without affecting the rest of the file, line returns included.</p>
  
  <p>Problems i've found is there are REPLICATED LINES; 'enable group' being one of them so i cant get findstr to work. </p>
  
  <p>Editing a specific LINE NUMBER wont work in this case because even though all files follow this format group [three] is often found on different lines.</p>
  
  <p>all [abc] titles are unique</p>
  
  <p>i want to use only batch if possible. thanks</p>
  
  <pre><code>; this is file information
  ; stuff
  ; last edited Thu Mar 23 01:13:18 2017
  
  [general]
  I/O = AB-1234
  second line = 0
  third line = 1
  
  [i/o one]
  enable group = 0
  enable board = 0
  memory size = 0
  
  [two]
  enable group = 0
  
  [three]
  enable group = 0
  enable board = 0
  memory size = 0
  </code></pre>