zoom key mapping

[-332FG-MasquitoBoi]

hey guys need some help, so ive been trying to map a new zoom keys so its more convenient then the "-" and "+" keys. whether i try re mapping on the keyboard or my thrustmasters 16000m hotas set up, it wont work in game except the default. dose anyone have any problems like this and if so what the solution? thank you again. o7