After a little bit of thinking I came up with this, and it works perfectly! ??
<?php
if ($comment->user_id == '0') {
echo comment_author_link();
} else {
$user_info = get_userdata($comment->user_id);
echo "<a href='" . get_option('siteurl') . "/author/" . $user_info->user_login . "'>" . $comment->comment_author . "</a>";
}
?>
??
