Well, OP, any more information? Going to answer any of the questions?
I only ask because you have returned, but haven’t posted.
As most everyone has said, no, the pastor can’t require Communion in the hand.
On the other hand, is this the hill you want to die on? If so, and you have verified that he this
is actually his rule, I would go to the church, copy of GIRM in hand and discuss it with him. If he doesn’t change the rule, I would call the Bishop’s office and take it up with them. Then take it as far as you are willing.
If it isn’t a hill you want to die on, I would tell my child that there are two approved ways to receive. That it is up to the person receiving, but this time the pastor wants everyone to receive the same way. I might even tell him that sometimes we do what the pastor says, due to obedience, as long as the request isn’t sinful. It is really up to you what you tell your child.