Frage zu OSC Modul Migration

[fulltilt]

Habe hier ein OSC Payment Modul und möchte dies im ZC integrieren.
Kann mir jemand bei den folgenden Änderungen weiterhelfen - ich müsste wissen in welchen Dateien bzw. Parts diese Änderungen durchzuführen sind:

2). files need to be modified:

checkout_process.php
find  out line 
  // lets start with the email confirmation
    $email_order = STORE_NAME . "\n" . 

and add in front of it 
  //payment cetrel
  if($payment != 'cetrel'){ 

find out the line 
  // send emails to other people
    if (SEND_EXTRA_ORDER_EMAILS_TO != '') {
      tep_mail('', SEND_EXTRA_ORDER_EMAILS_TO, EMAIL_TEXT_SUBJECT, $email_order, STORE_OWNER, STORE_OWNER_EMAIL_ADDRESS);
    }
and add after it 
  //payment cetrel
  }

find the line 
  $cart->reset(true);
and add after 
  //payment cetrel
  if($payment == 'cetrel'){
       tep_redirect('https://pos.cetrel.lu/jsp'.(MODULE_PAYMENT_CETREL_MODE == 'Test' ? 'cert' : '').'/intro.jsp?merchid='.MODULE_PAYMENT_CETREL_MERCHANT_ID.'&amount='.number_format($order->info['total'] * $currencies->currencies[$order->info['currency']]['value'], $currencies->currencies[$order->info['currency']]['decimal_places'], $currencies->currencies[$order->info['currency']]['decimal_point'],'').'&msgnr=200&trefnum='.$insert_id.'&currency='.$order->info['currency'].'&currencylabel='.$currencies->currencies[$order->info['currency']]['title'].'&language='.$languages_code.'');
  }
  //end payment cetrel

includes/application_top.php
find out the line with 
      tep_session_register('language');
      tep_session_register('languages_id');
and add after it 
      tep_session_register('languages_code');
find 

    $language = $lng->language['directory'];
    $languages_id = $lng->language['id'];
add after it 
    $languages_code = $lng->language['code'];