Thanks for your response Janardhan but I need the chart to be displayed as per the attachment rather than seperate charts. i.e. 1 dimension but with 2 expressions relating to different plots on the chart.
I agree with frankcrezee. You can use the combo chart to mimic the example. However, another way is to create two seperate charts and overlay both the charts. You can reduce the transperancy and also control the Move & Size properties.
.png "Luminary Alumni"){kind=icon}