[TYPO3] Extensions & eID -> initing extension manually

[Sebastian Böttger]

Hi there,

I'd like to use the eID functionality of TYPO3 for accessing the backend 
with an AJAX call.
With this call I'd like to use some functions of an extension. In this 
case "commerce".

But If I do so, I get the following error:

Fatal error: Class '' not found in 
/var/www/cms/typo3conf/ext/commerce/lib/class.tx_commerce_element_alib.php 
on line 200

Line 200 is just something like this:

            $this->conn_db = new $this->database_class();

Therefore $database_class is empty, because the extension is not inited.
Is it possible to load the extension manually for having all the 
functionality?

Or would there be a better approach?

Regards,
Sebastian Böttger