How to retrive months field

Dear friends

i have to create a report like..

Customer Jan Qty Feb Qty

A sum(all sales order qty in Jan)

B #VALUE! 204 200

C #VALUE! 208 200

D #VALUE! 212 200

how to retrive month field in above table

tables fields

kna1 kunnr ,name1

vbak vbeln , erdat

vbap meins , kwmeng

please suggest me the coding for this

regards

rohan