SORT FIELDS=(55,8,AQ,A)
 ALTSEQ CODE=(C1F1,C2F2)

The uppercase A (X'C1') is to collate at the same position as the numeral 1 (X'F1') and the uppercase B (X'C2') is to collate at the same position as the numeral 2 (X'F2').

Note that this ALTSEQ statement does NOT cause collating of A before or after 1, or of B before or after 2.