Fixed Position Tracking Camera

I’d like to implement in BGE something like Track-To for a fixed position Camera Object. The following code tracks the Target Object from a fixed position, but the camera’s Y-Axis is not always pointed upward.

CameraObject.alignAxisToVect(TargetObject.getVectTo(CameraObject)[1])
How this can be improved to keep the Camera Objects’s Y-Axis pointed upward? I expect the worldOrientation matrix is the ticket, but I’m a bit rusty when it comes to matrix rotation operations.

Thanks.
Doug

Never mind. Just found that I can use an Edit Object logic brick on the camera, with 3D Track To to the Target Object.