Hi,
I'm not sure if you are creating the order somewhere else and want to send the order creation email at that point, or if you want to have the order creation and the order creation email sending processes done on two different pages.
In the first case, it's really easy. When you call the save function of the class.order model you want to add a parameter $order->history->history_notified = 1; to the $order object so that the email will be sent.
In the second case, you'll want to use such code:
$orderClass->loadOrderNotification($order,'order_creation_notification');
$mail = hikashop_get('class.mail');
if(!empty($order->mail->dst_email)) {
$mail->sendMail($order->mail);
}
Note that this supposes that you have the $order object with the exact same content as when you create the order so it's going to be more difficult to do than for the first case.