Hi,

You can do it from the GUI.
You can simply change the Delta Cam Transf in the Origin.
However, Delta Cam Transf changes the camera rotation without any regard to where your tracker is located compared to your camera.
If the Vicon tracked cameras send tracking data that is not the center of your camera lens, then you will probably want to use the Delta Head Transf fields:

More on that here: https://aximmetry.com/learn/tutorials/for-aximmetry-de-users/experimenting-with-htc-vive-camera-tracking-using-unreal-scene/#calibrating-the-tracker-position

However, you might want to actually use the Aximmetry Camera Calibrator program. It also has Delta Head Transf field:
https://aximmetry.com/learn/tutorials/for-studio-operators/ptz-documentation/#calibration

Warmest regards,