str_replace and custom template

[LifesGreatestGift]

What am I doing wrong? I would like to do a string replace on postbit/postbit_legacy template. Find specific code, insert my custom template after it. Here is what I have and its not working.

PHP Code:

require_once(DIR . '/includes/class_template_parser.php'); 
$parser = new vB_TemplateParser('<span class="postcontrols">'); 
$parser->dom_doc = new vB_DomDocument($parser->fetch_dom_compatible()); 
$find = trim($parser->_parse_nodes($parser->dom_doc->childNodes())); 
$templater = vB_Template::create('my_custom_template'); 
$parser = new vB_TemplateParser($templater); 
$parser->dom_doc = new vB_DomDocument($parser->fetch_dom_compatible()); 
$replace = trim($parser->_parse_nodes($parser->dom_doc->childNodes())); 
$vbulletin->templatecache['postbit'] = str_replace($find, $find . $replace, $vbulletin->templatecache['postbit']);
$vbulletin->templatecache['postbit_legacy'] = str_replace($find, $find . $replace, $vbulletin->templatecache['postbit_legacy']); 
unset($find, $replace); 


This is using parse_templates.

I tried this in postbit_display_complete and it doesnt work either.

PHP Code:

$find = '<span class="postcontrols">'; 
$replace = vB_Template::create('my_custom_template'); 
$vbulletin->templatecache['postbit_legacy'] = str_replace($find, $find . $replace, $vbulletin->templatecache['postbit_legacy']); 
$templater->render(); 
unset($find, $replace); 


Any help would be appreciated.