copy customer fields from vbap to vbrp, lips to vbrp.

sap will automatically copy the append fields of vbap to vbrp.(assume the append fields name in vbap and vbrp are just the same ).
if you want to copy customer fields from lips to vbrp,
you should make change the userexit_fill_vbrk_vbrp. (LV60AA93 Line No.476 : the last line of LV60AA93)