Crystal Reports 2011 Running total on columns in Cross Tab

Hi All,

I am having a requirement where in we created a cross tab with Months in Rows. years in columns and quantity in details. But when I do the running total for Quantity, it is summing across the rows and I am not able to get the data as below:

Please let me know how I can use the Running total on columns in a cross tab, below is my expected output.

2011
Quantity RunningTotalOfQuantity Jan 100 100 Feb 200 300 Mar 300 600 Apr 400 1000 May 500 1500 Jun 600 2100 Jul 700 2800 Aug 800 3600 Sep 900 4500 Oct 1000 5500 Nov 1100 6600 Dec 1200 7800

Thanks