Currently my Grid Surface chart is doing a "global zoom" quite nicely via:

NZoomTool zt = new NZoomTool();
zt.BeginDragMouseCommand = new NMouseCommand(MouseAction.Wheel, MouseButton.Middle, 0);
zt.ZoomStep = 16;
chartControl.Controller.Tools.Add(zt);


However, I'd like to catch Ctrl+Wheel as a way of affecting the chart's "Height" property.  How can I catch the Ctrl+Wheel to do this?   I can't seem to adjust height in a wheel handler without also getting the zoom from the NZoomTool.