A friendly tip if you have all the units in same group would be to use
"_x moveincargo vehiclename" foreach units group this
in the leaders init field.
@Artak, as it's multiplayer, i wouldn't recommend this one.
Remember what has happened, when those "think_on_my_own_way" guys decided not to choose
the groupleader, and then they even disabled the Leader's AI
slot in the player selection menu.
Ya know their yelling when all were starting in the water instead of inside the chopper ;D
@PimpD - stick to Artak's first suggestion: this MoveIncargo heli
in each units init field, or unitname MoveInCargo heli
in the init.sqs file.
~S~ CD