I would not suggest you try to get directly to the Dolphin from your resort. Plan to go to Fresh on a day you will be visiting either the Studios or Epcot. As another poster mentioned, you can either boat or walk from the Studios to the Dolphin. You can also do this from the Epcot International Gateway. The Friendship boats travel from the Epcto IG to the Studios all day stopping at the Beach/Yacht clubs, Boardwalk, and Swan/Dolphin along the route. Trying to get directly from one resort to another takes a lot of time.
ps........I also agree that if you want to do this and fast your only option is a taxi.