INIT field of some grp Member must read :
Morons = Units Group This
And then a trigger or a WP could read :
"_x moveinCargo Heli1" foreach Morons
(...where "heli1" is the NAMED chopper - use the name field when U create the bird, right?!)
PS. ya can also kick 'em inside the bird right away - just put that spell in the INIT of a group member.