Join Date: Aug 1999
Location: Alexandria, VA, USA NW Platinum Elite Since 1999, United GoldMM, Hyatt Discoverist, SPG Gold, Hilton Diamond, Hertz #1 Gold, IC Ambassador
Posts: 7,451
Fly the 2 flights, get the silver status and then use it to get your upgrades on NW since both programs offer reciprocal upgrade and bonus mileage. I don't think there is anything to preclude you from using only CO, unless it specifically states this in the rules of your letter.