Convert smileys in recent comment code

Hi, I’m using the following code in my sidebar:

<?php
global $wpdb;
$sql = "SELECT DISTINCT ID, post_title, post_password, comment_ID,
comment_post_ID, comment_author, comment_date_gmt, comment_approved,
comment_type,comment_author_url,
SUBSTRING(comment_content,1,60) AS com_excerpt
FROM $wpdb->comments
LEFT OUTER JOIN $wpdb->posts ON ($wpdb->comments.comment_post_ID =
$wpdb->posts.ID)
WHERE comment_approved = '1' AND comment_type = '' AND
post_password = ''
ORDER BY comment_date_gmt DESC
LIMIT 5";
$comments = $wpdb->get_results($sql);
$output = $pre_HTML;
$output .= "\n<ul class='tweets'>";
foreach ($comments as $comment) {
$output .= "\n<li>". strip_tags($comment->com_excerpt) ."... <span class=\"small\">by <strong>".strip_tags($comment->comment_author) ."</strong> on <a href=\"". get_permalink($comment->ID) ."\">". $comment->post_title ."</a></span></li>";
}
$output .= "\n</ul>";
$output .= $post_HTML;
echo $output;?>

It works great, but I’d like it to display any smileys like 🙂 as their smiley, not the smiley code.

I know there are features like convert_smileys but how would I get it working on this?

Thanks