Originally Posted by
f4freeJunior
You should get access on the basis of your boarding pass ZRH-GXX flight. The idea is not to tell them you are flying to BEG first and only show them the longhaul bp.
Are you sure it will work, they may realize the OP is currently flying on a different ticket plus they may be aware that the trip including ZRH-XXX flight has not commenced yet in BEG.
It depends on what kind of information the front desk staff can see after a BP is scanned and how perceptive they actually are.