Eh, English was a little tough to interpret, but I'll try.

If you're doing 400km/wk and you only have a 100km ride, you'll do fine. Since a trainer is usually 10-20% harder than the road, just make sure you can do the 100km on the trainer. Learn to pace yourself for 3.5hrs, that is my only real recommendation. Find out when you should eat and how much to drink; don't eat when unnecessary. You'll do fine.