! Set up your IOL into a string
LET apCheckDtlDst$="wrk.InvoiceNo$,wrk.InvoiceDate$,wrk.Comment$,wrk.PaymentAmt,wrk.DiscountAmt,wrk.CheckEntryNo$,wrk.LineKey$"
! Then you will read from $$ into that IOL
READ DATA FROM $$ TO IOL=apCheckDtlDst$
! You can also clear a 4.x record using this method
READ DATA FROM $$,REC=Record$ TO IOL=RecordIOL$
READ DATA FROM $$,REC=cust$ TO IOL=IOL(custfh)