Hi Sai
As Ramesh told, you can directly read the value of EKPO-ELIKZ (for all the materials of PO).
Or,
do as follows: ( Pseudo code)
Loop at all POs ( from EKKO)
Call the BAPI BAPI_PO_GETDETAIL1 by passing the EBELN.
It wll return a structure BAPIMEPOHEADER
In the structure look for the vaieable BAPIMEPOHEADER-STATUS
Endloop.
This how you can find out.
Regards,
Venkat