lw_bape_prps-wbs_element = lw_wbs1-wbs_element.
lw_bape_prps-customer_id = lw_wbs1-customer_id.
lw_bape_prps-customer_grp = lw_wbs1-customer_group.
lw_bape_prps-customer_geo = lw_wbs1-customer_geo.
lw_extension-structure = 'BAPI_TE_WBS_ELEMENT'.
lw_extension-valuepart1 = lw_bape_prps+0(240).
lw_extension-valuepart2 = lw_bape_prps+240(240).----------------------------in this line it is encounting error.
lw_extension-valuepart3 = lw_bape_prps+480(185).
APPEND lw_extension TO lt_extension.
CLEAR lw_extension.