pitching the camera at a reference point?

Hi, I intend to add this feature whereby when the user zooms in/out on the 3d globe, the camera will be pitched up/down relative to the camera cartographic height from the globe. While pitching, the camera would at least still stays focused on what the user's choose to zoom in on. It would look much like the columbus view but still in 3D globe.

As a start, I'm implementing this behavior at the screenSpaceEventType handler

}, Cesium.ScreenSpaceEventType.PINCH_MOVE);

The camera's able to do the pitching but the camera's aim too far up to the north (which sees the space rather than the globe) and it doesn't focus where I'm trying to zoom at. Is there any possible alternative methods rather than using camera.pitch?