If DHL delivers the product themselves, e.g. when using "DHL Express" service, then you can pay the Customs fees online before the item arrives, and can call DHL, while the package is en route, and have them deliver to a different address, provided that new address is within the same "tax/duty" destination Country/Province/State etc..I don't know what you do when the DHL service is the one that hands your package over to the local national postal service to complete the last leg, though. Before your package arrives in the destination Country, DHL usually knows what the Customs fees are, for most simple things that have well defined tax and duty codes. So, chances are you may be able to just call DHL and pay Customs with Credit Card over the phone, or pay online using the url,
http://www.dhl.ca/MyDelivery, where you enter the DHL WAYBILL number to see what your Customs fees are.