The $XABKEY_STORE macro moves user-specified values into fields
    of the specified XABKEY. The expanded $XABKEY_STORE code executes
    at run time on a previously initialized (allocated) XABKEY, in
    contrast to the $XABKEY macro, which initializes the XABKEY at
    assembly time. The $XABKEY_STORE macro must reside in a code
    program section.

    Format

      $XABKEY_STORE  XAB=xabkey-address,

                     COLTBL=#collating-table-address,

                     DAN=#data-bucket-area-number,

                     DFL=#data-bucket-fill-size,

                     DTP={BN2|DBN2|BN4|DBN4|BN8|DBN8|IN2

                     |DIN2|IN4|DIN4|IN8|DIN8|COL|DCOL

                     |PAC|DPAC|STG|DSTG},

                     FLG=<CHG DAT_NCMPR DUP IDX_NCMPR KEY_NCMPR NUL>,

                     IAN=#index-bucket-area-number,

                     IFL=#index-bucket-fill-size,

                     KNM=key-name-buffer-address,

                     LAN=#lowest-level-index-area-number,

                     NUL=#null-key-value,

                     NXT=next-xab-address,

                     POS=<position,...>,

                     PROLOG=#prolog-level,

                     REF=#key-of-reference-value,

                     SIZ=<size,...>