Magento – SOAP order inserting: How to stipulate the payment method

Here you have a php example (from the Magento API manual) on how to create an order with the needed calls:

/**
 * Example of order creation
 * Preconditionsare as follows:
 * 1. Create a customer
 * 2. Сreate a simple product */

$user = 'apiUser';
$password = 'apiKey';
    $proxy = new SoapClient('http://magentohost/api/v2_soap/?wsdl');
    $sessionId = $proxy->login($user, $password);
    $cartId = $proxy->shoppingCartCreate($sessionId, 1);
    // load the customer list and select the first customer from the list
    $customerList = $proxy->customerCustomerList($sessionId, array());
    $customer = (array) $customerList[0];
    $customer['mode'] = 'customer';
    $proxy->shoppingCartCustomerSet($sessionId, $cartId, $customer);
    // load the product list and select the first product from the list
    $productList = $proxy->catalogProductList($sessionId);
    $product = (array) $productList[0];
    $product['qty'] = 1;
    $proxy->shoppingCartProductAdd($sessionId, $cartId, array($product));

    $address = array(
        array(
            'mode' => 'shipping',
            'firstname' => $customer['firstname'],
            'lastname' => $customer['lastname'],
            'street' => 'street address',
            'city' => 'city',
            'region' => 'region',
            'telephone' => 'phone number',
            'postcode' => 'postcode',
            'country_id' => 'country ID',
            'is_default_shipping' => 0,
            'is_default_billing' => 0
        ),
        array(
            'mode' => 'billing',
            'firstname' => $customer['firstname'],
            'lastname' => $customer['lastname'],
            'street' => 'street address',
            'city' => 'city',
            'region' => 'region',
            'telephone' => 'phone number',
            'postcode' => 'postcode',
            'country_id' => 'country ID',
            'is_default_shipping' => 0,
            'is_default_billing' => 0
        ),
    );
     // add customer address
    $proxy->shoppingCartCustomerAddresses($sessionId, $cartId, $address);
    // add shipping method
    $proxy->shoppingCartShippingMethod($sessionId, $cartId, 'flatrate_flatrate');

    $paymentMethod =  array(
        'po_number' => null,
        'method' => 'checkmo',
        'cc_cid' => null,
        'cc_owner' => null,
        'cc_number' => null,
        'cc_type' => null,
        'cc_exp_year' => null,
        'cc_exp_month' => null
    );
     // add payment method
    $proxy->shoppingCartPaymentMethod($sessionId, $cartId, $paymentMethod);
     // place the order
    $orderId = $proxy->shoppingCartOrder($sessionId, $cartId, null, null);

If I'm not mistaken (could be, was a while back since I changed something in payment methods) each payment method has a block class Info and a corresponding info.phtml template.

For example, looking at moneybookers it has the class Phoenix_Moneybookers_Block_Info with the template moneybookers/info.phtml This is the file which is included in the emails so if you include the QR code there (or whichever payment method you want to change) it should be displayed correctly in the email.