How I get realusername i hybrid mode

[userform3]

Helo ,

In the thread shall be show real username in hybrid mode.
How can I this make?

My first try was make a plugin

Plugins & Products --> Plugin Manager

Product: vBulletin
Hook Location: showthread_start
Titel: Realname
Execution Order: 5

Plugin PHP Code:

PHP Code:

$hook_query_fields .= ' , userfield.* ';
$hook_query_joins = "LEFT JOIN " . TABLE_PREFIX . "userfield AS userfield ON(userfield.userid = thread.postuserid)";
$hook_query_where = ' post.threadid '; 


It's not work.

In the file showthread.php in line 1176 following i found variables:

PHP Code:

$hook_query_fields = $hook_query_joins = $hook_query_where = ''; 


And after this query and in line 1448 the same.
It seems as if the hook was not passed to the file showthread.php

What is the error?

Vbulletin 4.1.4 forum.

Greeting
userform3