Put cherries, juice and all, in saucepan with the sugar. Bring to a boil. Add cherry gelatin; stir well. Add pineapple and nuts. Chill. Make the day before so it will gel.
Robin - do you mean cherry pie filling? If not, where would I find "pie cherries"?
Editor's Note: Pie cherries are found in cans just like cherry pie filling, but usually are whole cherries packed in water or a sugar solution. These would be a sour or tart cherry. I know there is an Oregon Fruit Products brand available in grocery stores in the Northwest, maybe nationwide.