From your includes/templates/<your_template>/templates/wpcallback_default.php file, I could probably add an email routine, below the quoted block below, in order to be sent to your global store email address.
<?php
//echo '<WPDISPLAY ITEM=banner>';
if ($testMode !== 0) {echo WP_TEST_HEADING . "<br /><br />";}
echo WP_CONTACT_HEADING . "<br /><br />";
echo $name . "<br/>";
echo $address . "<br />";
echo $postcode . "<br />";
echo $country . "<br />";
echo "Tel: " . $tel . "<br />";
echo "Email: " . $email . "<br /><br />";
echo WP_PAYMENT_HEADING . "<br /><br />";
echo $authAmountString . " has been debited from your " . $cardType . " card.<br />";
echo "Our ref: " . $cartId . "<br />";
echo "Your WorldPay Transaction ID is " . $transId . "<br />";
?>
However I'd rather hear from the DEV team to see if this type of procedure is permitted on e-commerce programming policy. If it is, it could probably be arranged.