This attribute sets the vector toward which the Body Vector is constrained.
Astrogator <Satellite Object Path> SetValue <Attribute Path>.ConstraintVector {Value}
The value can be any Vector that is defined in the Vector Geometry Tool of the Select Reference Axes window. Make certain that the name is copied exactly. If you require additional vectors, you can define them using the Vector Geometry Tool.
Astrogator */Satellite/Satellite1 SetValue MainSequence.SegmentList.Maneuver.ImpulsiveMnvr.ConstraintVector "CentralBody/Earth Angular_Velocity"
STK Programming Interface 11.0.1