This might do it, if I correctly understood your wishes:
1. Add this to your init.sqf:
Code:
onTeamSwitch "selectPlayer (leader _from); {_x doFollow leader _from} foreach units _from; selectPlayer _to;";
(see this thread for explanation)
2. Add a playable unit well away from any action - say a civilian medic, with this allowdamage false; in the unit's init field (just in case
)
3. Give your player group appropriate waypoints
Start the mission & at the relevant time, team switch to the civ. The player group should continue along the waypoints. You can switch back when ready.