editing header-extensions.php in child theme

Hi there,

First of all, I love this theme. Very useful and well designed!

I’m editing how the header image resizes and to accomplish the desired effect, I need to add a div around the header image in the header-extensions.php file, like this:

<div id="header-border">

<a href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>"><img src="<?php echo $header_image; ?>" class="header-image" width="<?php echo get_custom_header()->width; ?>" height="<?php echo get_custom_header()->height; ?>" alt="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>"></a>

</div>	<!-- end header-border -->

I’m using a child theme and everything was working fine until I reached this point. When I made a copy of header-extensions.php and added it to the child theme folder, it didn’t override the existing header-extensions.php file.

As a test, I edited this file in the parent theme and this extra div works great, but I obviously don’t want to edit the parent theme files. What should I do to make the child header-extensions.php file override the parent file?

Thanks in advance,
Ricky