If I understand the moves mechanics correctly, a poke can only relearn a move (egg move or otherwise) that is in its move list, and not of its pre-evolution's. Thus, Hitmon-whatever cannot relearn Helping Hand as it is a Tyrogue only move. Just tested this out with a Hitmonchan that I got in a trade with no egg moves whatsoever, so it should be correct. In conclusion, to get your Helping Hand Hitmontop, you have to do what DHR-107 said. I.e. breed Tyrogue with whatever egg moves you want, bring it to move relearner, relearn Helping Hand THEN only you evolve it.