1. create a player unit
2. create a DIFFERENT group unit. NAME it "myUnit"
3. give him a move waypoint, so that it moves when the commands are given to him. (EDIT: I could reproduce it on a stationary unit as well)
4. run the following code on him:
[] spawn {
myUnit setUnitPos "MIDDLE";
sleep 5;
(group myUnit) setBehaviour "SAFE";
myUnit setUnitPos "UP";
};