To make it dynamic, manipulate the BDC code like belw :
v_index = 0.
DO V_count. "where V_count should contain total number of entries to be copied.
v_index = v_index + 1.
concatenate 'RSCSEL_255-SLOW_I(' v_index ')' INTO v_string.
perform bdc_field using v_string
v_value. "v_value should contain value to be copied. This will change with every loop iteration.
ENDDO.
