Compaq COBOL AAQ2G1FTK - Manual (Page 122)

Handling Nonnumeric Data
3.6 Using the MOVE Statement
3.6.7 Using Reference Modification
You can use reference modification to define a subset of a data item by specifying
its leftmost character position and length. Reference modification is valid
anywhere an alphanumeric identifier is allowed unless specific rules for a general
format prohibit it. The following is an example of reference modification:
WORKING-STORAGE SECTION.
01
ITEMA PIC X(10) VALUE IS "XYZABCDEFG".
.
.
.
MOVE ITEMA(4:3) TO...
IDENTIFIER VALUE
ITEMA (4:3) ABC
For more information on reference modification rules, refer to the Compaq
COBOL Reference Manual.
3–12 Handling Nonnumeric Data