参考：

Fires when clicking on the plot background. The this keyword refers to
the chart object itself. One parameter,event,is passed to the
function. This contains common event information based on jQuery or
MooTools depending on which library is used as the base for
Highcharts.

Information on the clicked spot can be found through event.xAxis and
event.yAxis,which are arrays containing the axes of each dimension
and each axis’ value at the clicked spot. The primary axes are
event.xAxis[0] and event.yAxis[0]. Remember the unit of a datetime
axis is milliseconds since 1970-01-01 00:00:00.

码：

chart: {
    type: 'column',events: {
        click: function () {
            alert('chart clicked');
        }            
    }
}

演示：http://jsfiddle.net/DYNhr/