Usage of include WordPress on external page

I run the following :

<div id="blog">
    	  <div id="blog1">
    	  <a href="http://advanceperformance.com/news/?cat=14"><img src="images/feed_head_whatsnew.gif" width="250" height="25" alt="" /></a>
<?php query_posts('showposts=3&cat=14'); ?>
      <?php while (have_posts()): the_post(); ?>
	                       <div class="postmeta2">
	                           <div class="meta2inner">
	                               <div class="pday"><?php the_time('j'); ?></div>
	                               <div class="pmonth"><?php the_time('M/y'); ?></div>
	                           </div>
                    </div>
        <div class="text">

                    <h4><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h4>

        <a href="<?php the_permalink(); ?>">Read More...</a>
        </div>
        <br />
        <?php endwhile; ?>

And it works great but I am having trouble using
<?php the_post_thumbnail();?>

In order to get the first image out of the post and display.

Any help would be greatly appreciated.

Thanks