Hi..
You get planning cost 1 from MBEW table using exit EXIT_SAPLKEAB_001.
Refer to below example for EXIT_SAPLKEAB_001.
DATA: LINE_ITEM_XXXX LIKE CE1xxxx.(xxxx means your operating concern)
CASE ERKRS.
WHEN 'xxxx'.
LINE_ITEM_XXXX = EP_SOURCE.
SELECT SINGLE ZPLP1
INTO LINE_ITEM_XXXX-VVXXX
FROM MBEW
WHERE MATNR = LINE_ITEM_XXXX-ARTRN
AND BWKEY = LINE_ITEM-WERKS.
EP_TARGET = LINE_ITEM_XXXX.
ENDCASE.