title: Check if Windows batch variable starts with a specific string
body: <p>How can I find out (with Windows a batch command), if, for example, a variable starts with <code>ABC</code>?</p>
  <p>I know that I can search for variables if I know the whole content (<code>if &quot;%variable%&quot;==&quot;abc&quot;</code>), but I want that it only looks after the beginning.</p>
  <p>I also need it to find out where the batch file is located, so if there is a other command that reveals the file's location, please let me know.</p>