I would like to see this in action, has anyone tried this. I wonder what would happen if you put in the WP# when you purchase the ticket. If not could it have someting to do with the agreement HP and NW have already which limits WP earning to:

"Flights between Phoenix/Las Vegas and Los Angeles/San Francisco when connecting on Northwest Airlines flights to/from Asia."

Flight fund earing on NW is limited to:

"Mileage credit is limited to transpacific itineraries, including Honolulu, and between Asia destinations. Mileage will not be awarded on domestic flights which are not part of a transpacific itinerary."

BSL