[TYPO3-commerce] Payment extension Eurocashnet

[till hess]

We are writing a payment extension for commerce using Eurocash-Net als 
Provider/Acquirer.
In our extension we call Eurocash via URL and GET-parameters, Eurocash 
calls us back using a preconfigured URL.
We are not clear on what the page Eurocash calls in case of successful 
payment should contain - we have been using the normal checkout plugin 
and hookup via hasSpecialFinishingForm().
If we do it like this nothing happens - tx_commerce just asks for the 
checkout data again so no further processing happens.
So the question is how do we enter commerce again in case of successful 
payment to finish the process? Thanks for your help.

interSales AG Internet Commerce
Till Heß