Hi Akshath,
my question was, why you can't use EQ but must use CP.
Otherwise you could use
SELECT ... FROM MARA APPENDING TABLE lt_mpn_matnr
FOR ALL ENTRIES IN it_mara WHERE mfrpn = it_mara-mfrpn .
Therefore it would be optimal, if it_mara would only contain entries, where MFRPN is filled and unique in table.
Regards,
Klaus