title: How to make get_header() call a custom header file located in a sub-folder of the theme?
body: <p>From a PHP template file located in a sub-folder of my WP theme folder (<code>my_theme/subfolder/my_file.php</code>) I want to use <code>get_header()</code> and call a custom <code>header-new.php</code> located in the same sub-folder. </p>
  
  <p>Instead, <code>get_header(header-new)</code> loads <code>header.php</code> located in my theme root folder. How to fix that problem?</p>