Hi onno, thank for your reply.
I don't want to be whining, but can you please explain a bit what the issue is? I would think that the only thing you guys would have to do is add a standard PostNL-deliverypoint-lookup-component to the site which allows the customer to select an alternatieve delivery-address. A lot of Dutch webshops offer this, even some small ones.
Does PostNL charge you for these transactions?