title: batch start persist specific variable
body: <p>I have a.bat which has a variable <code>%errorlevel%</code>, and the following line which calls b.bat: </p>
  
  <pre><code>start /wait cmd /c b.bat
  </code></pre>
  
  <p>If <code>b.bat</code> sets the <code>%errorlevel%</code> (e.g. <code>errorlevel = 5</code>)</p>
  
  <p>How is it possible for me to persist only this <code>%errorlevel%</code> variable in <code>a.bat</code>, without using the CALL command.</p>
  
  <p>The reason I don't want to use CALL is because <code>b.bat</code> contains some variables that I do not want to persist.</p>