Setting Remotes Area Dhl

Hello,
I have a problem.
I need to set the DHL courier shipments. DHL is the only carrier that I use.
My shipments are all in Italian.
With Dhl in Italy there are CAP Remotes Area for which the shipment was a higher cost. Are about 1000 CAP.
For all CAP normal use shipment based on weight.
The problem is that when a customer buys and its area is remote, the shipping is more expensive and do not want to ask for an additional fee after the purchase, it would be unprofessional.

I ask if anyone knows an extension that allows you to set for about 1000 CAP Italians a greater cost, always based on weight.

I searched and the extension that appears to be useful for me is this: http://www.opencart.com/index.php?route ... ion_id=436

but I'm not sure yet.

Could someone help me?

You can ask the author some pre-sale questions. He may be able to make it do what you need, it it doesn't already do it.