Create a varible on 0CALMONTH in query designer, which have interval and mandatory properties.
Use can use formula:-
Opening stock quantity= Closing quantity(0TOTALSTCK) + Issued quantity(0ISSTOTSTCK) - Receipt quantity(0RECTOTSTCK)
Opening stock value = Closing value(0VALSTCKVAL) + Issued value(0ISSVS_VAL) - Receipt value(0RECVS_VAL)
Also u can use both MC.9 and MB5B for validating data.