How to add this link beside thread subject

[MGadAllah]

Hi
I've an account with the service www.addthis.com
I'd like to know where exactly to add this link

كود :

<!-- AddThis Bookmark Button BEGIN -->
<script type="text/javascript">
  addthis_url    = location.href;  
  addthis_title  = document.title;  
  addthis_pub    = 'mgadallah';    
</script><script type="text/javascript" src="http://s7.addthis.com/js/addthis_widget.php?v=12" ></script>
<!-- AddThis Bookmark Button END -->

to let it appear like this:

I've tried to add it to different templates but was really unluck to let it be placed at this exact place.

I hope you can help me.
Thanks