Data Grid Colomns in the colomns

Question

Hi


i need a column in the grid should be sub divided and data should be retrieved according to that.
please refer the screen shot



In above screen shot, 
Worked days, LOPDays, Revoke LOPdays etc are the columns .
and they have sub colomns i.e 2012-06, 2013-06 which are coming from the combobox
selected values.
so how can i retrieve those subcolumns values?
i am able to retrieve the worked days of one single period and showing in one column. but i need to show as above screen shot.
Can anybody please tell me if possible give a misscall to my number 9703765617.
its very important for me, tried a lot but didnt get.
Thank you in advance.