create a marker called rtb and execute the task in debug console of init.sqf
[[_rtbId], WEST, ["Escort the scientist to base for debriefing.", "Escort to base", "rtb"],getMarkerPos 'rtb', "AUTOASSIGNED", 0, true, true, "Move", true ] call BIS_fnc_setTask;
result:
new 3d task icon in world is visible.
new task info on map is not.