[Boofo]

Try this:

    if ($vbulletin->options['legacypostbit'])  
    {  
        $find = trim(preg_replace('#^\$final_rendered = \'(.*)\';$#s', '\\1', compile_template('<vb:if condition="$post[\'postid\'] AND $post[\'threadid\'] AND !$show[\'moderated\']"> 
                    <a name="post{vb:raw post.postid}" href="{vb:link thread, {vb:raw thread}, {vb:raw pageinfo_post}}#post{vb:raw post.postid}" class="<vb:if condition="$show[\'inlinemod\']">ie</vb:if>postcounter">#{vb:raw post.postcount}</a><a id="postcount{vb:raw post.postid}" name="{vb:raw post.postcount}"></a> 
                </vb:if>')));
        $add = "testing..."; 
        $vbulletin->templatecache['postbit_legacy'] = str_replace($find, $find . $add, $vbulletin->templatecache['postbit_legacy']);      
    }