Move point in Z direction while LOCKING X,Y coordinates

I'm currently working in a 3D Stereo dgn file, in ISSD (Imagestation stereo display), within microstation V8i, where I need to move features (more than 50,000) in the Z direction to obtain height information on the feature.

Is there a way to lock the X,Y coordinates while moving in the Z direction while maintaining the XY coordinate integrity of the feature cell?

I've tried messing around with the lock settings in microstation and ACS Plane setting with no luck. 

I appreciate any information, thanks!