If the byte is a true binary value, you can move that one byte to the low-order byte of a 2-byte comp field.
01 comp-num pic 9(4) comp.
01 comp-num-r redefines the-comp-num.
05 filler pic x.
05 calc-byte pic x.
in the procedure code,
move zeros to comp-num
move the input byte to calc-byte.
comp-num can now be used to subscript an array (or it can be incremented and then used as the subscript). it is not displayable, but is completely useful for calculating/incrementing.