Two pax on same PNR, but one has to skip first leg
I am seeking suggestions on this dilemma. My son and I will fly from IAD-EWR-xxx. He will have an externship in NYC. So, it is more convenient for him to skip the first leg. Is there any solution other than paying $250 changing fee + fare differences? If I print out his boarding pass, will the gate agent scan it even my son is not physically present at the gate? Or is there any chance that the check-in agent at IAD be persuaded? Thank you for your suggestions in advance.