When I have not had any orange marmalade and had zucchini in my garden I did the following.
It is delicious.

Zucchini Dish

6 c. zucchini squash
6 c. sugar
3T. lemon juice
1 can crushed pineapple (this should be drained)
1 6 oz. orange Jell-O (can use any flavor for other occasions)

You will need to peel squash, and remove the seeds. Grate the zucchini. Mix the lemon juice, pineapple and sugar in a large pot. Add grated zucchini. Bring this to a boil and simmer 15 to 20 minutes. Add Jell-O (or other brand) bringing to a boil. Boil for 1 minute. After this you
can put into hot jars and seal or keep in refrigerator.
Shirley in MS

http://www.nancyskitchen.com