You will most likely need to modify your theme.
Using the default kubrick theme, here is how I put the query string in the post title.. this is in the main index template, can you see where I made the modification?
Code:
<h2><a href="<?php the_permalink() ?><?php echo (isset($_GET['ref'])) ? '?ref='.$_GET['ref'] : ''; ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></h2>
Hope that gives you an idea.