You do not need to include any DM files, also, you were meant to change the code I posted to suit your situation.
PHP Code:
define('THIS_SCRIPT', 'createVbUserBlogDev');
require_once('./global.php');
$userdmBU =& datamanager_init('Blog_User', $vbulletin, ERRTYPE_ARRAY);
$userdmBU->set('bloguserid', 65);
$userdmBU->set('title', 'This is a test Title');
$userdmBU->save();