title: Rename multiple files using cmd
body: <p>I'm trying to rename multiple files in a folder using CMD prompt. Following code renames as <code>file1</code>, <code>file2</code>,... but I want to append from a middle value like <code>file51</code>, <code>file52</code>,...</p>
  <pre><code>SET /a &quot;#=&quot;
  FOR %_ IN (*) DO (
    CALL SET /A &quot;#=#+1&quot;
    CALL REN &quot;%~f_&quot; &quot;file%#%.jpg&quot; )
  </code></pre>
  <p>If I use <code>SET /a &quot;#=51&quot;</code> in first line, it is getting executed for every loop, initializing the value to <code>51</code> every time.
  What am I missing out?</p>