There is only 2 ways to do it.
Book a package with 1-day MYW tickets, but then you can't use an AP discount on the room.
The other way is to rent points (sometimes actually cheaper than AP discount) from a DVC member and then you can get the dining plan since you have a DVC reservation. I rented points for end of April and am paying $140 a night for Boardwalk Villas. No way an AP discount would have touched that price, so I am very happy. Plus, you can use the dining plan, but you have to tell them before you arrive and pay for it when you check it.