If a hen goes broody, you can give her fake eggs to sit on. After a week or so, if she is still acting nicely broody, order the chicks to arrive in about two weeks (so the chicks arrive when she has been sitting for three weeks, plus or minus a few days depending on what day of the week she started.)
Obviously that only works if the hatchery has the right chicks available to order at the right time.
If you are trying to place an order months in advance. I would probably just plan on brooding them yourself. If a hen happens to go broody about the right time, you could change plans and have her raise the chicks. If a hen goes broody a little bit too early, give her fake eggs and see what happens: some hens will sit for 4 or 5 weeks before they give up, so you might get lucky. If a hen starts sitting more than about 5 weeks before the chicks would arrive, I would try to break the broodiness, because she will probably not still be sitting by the time the chicks arrive.