I guess this is what you need. This script will show the radio options only for the unit which you choose as 'player'. This is supposed to be the leader of the group.
Units set to 'playable' will not see and will not be able to activate the radio commands. If the player who started the mission as the unit you set to 'player' dies and respaws to another unit who were originally set to 'playable' WILL BE ABLE to use the radio....
You have to start the script at the very beginning of the mission.
I hope it's not too confusing, but believe me this definetly works...
1 setRadioMsg "NULL"
2 setRadioMsg "NULL"
3 setRadioMsg "NULL"
?(player == leader YourGroupName): 1 setRadioMsg "Call in Reinforcemen"
?(player == leader YourGroupName): 2 setRadioMsg "Call in Airstrike"
?(player == leader YourGroupName): 3 setRadioMsg "blablablabla"
~1
exit