Resource Related Billing

Hi,

I need to transfer a field "Work centre" from (Tcode DP91) Resource related billing to sales Item.

I wrote below code in exit EXIT_SAPLV46H_001. Exit is active in CMOD.

c_vbapkom-ZARBPL = I_SDSM_DLI-ARBPL.

When I debug the value is available in c_vbapkom-ZARBPL. But its not stored in table VBAP.

Pls help me.

REgards,

BM