title: Batch file - reading csv value and change value
body: <p>I have an very large csv file with x,y,z data. What I am looking to do is write a batch file that pull all the values from column y and change the values negative (they are all positive currently). I have not had any luck so far with this. If there is someone out there that can help me out with this I would greatly appreciate it. I am fairly new to writing batch files and have not figured this one out. Again any help is very much appreciated.</p>
  
  <p>I have tried </p>
  
  <pre><code>@echo off
  SETLOCAL
  
  for /f "tokens=2 delim=," %%A in ("Book1.csv") do(
      echo "%%A"* -1 &gt;&gt;testfile.csv)
  </code></pre>
  
  <p>I am not getting the column values. I get csv with %a in one column</p>
  
  <p>The csv file I have looks something like this...</p>
  
  <pre><code>45.123,78.564,123
  44.654,77.256,23
  44.789,74.123,78
  </code></pre>
  
  <p>I am attempting to change the y values so they are negative...</p>
  
  <pre><code>45.123,-78.564,123
  44.654,-77.256,23
  44.789,-74.123,78
  </code></pre>