title: Duplicate first column of csv using command line [edited]
body: <p>I'm trying to duplicate and prepend the first column of a csv with a date from Windows command line.</p>
  
  <p>I've tried powershell -replace with RegEx and For /f but I can't get it.</p>
  
  <p>Example simplified CSV:</p>
  
  <p>col a, col b<br>
  IE00abcdefgh,text<br>
  IE00defghijk,text</p>
  
  <p>Column A always starts with IE00 and then 8 more random characters.</p>
  
  <p>Desired Output:</p>
  
  <p>newcol, col a ,col b<br>
  20200428-IE00abcdefgh,IE00abcdefgh,text<br>
  20200428-IE00defghijk,IE00defghijk,text  </p>
  
  <p>I already have the date to prepend in a %%date%% variable.</p>
  
  <p>Thanks in advance,</p>