Babylark, I've never tried growing Jack-in-the-Pulpit inside because mine drop seeds and the squirrels plant them all around the yard. It's not clear to me whether the seed must be fresh to germinate, but I suspect cold is a factor.
You might check out the directions Tom Clothier provides--there are a couple of entries for Arisaema (the species we have here is triphyllum).
http://tomclothier.hort.net/page02.html
If I had lots of seed, I would be tempted to plant them in a pot (covered with hardware cloth to keep the squirrels out) outside now and see if them come up on their own over time. If you don't get them to go, buy a plant or beg one from someone and be patient. They take a number of years to produce female flowers--and thus fruits. Good luck!