The BEGIN_LOOP command is used in conjunction with the END_LOOP command to form a processing loop.
The loop formed is repeated the number of times specified by the FROM, TO and STEP parameters. Optionally a field can be nominated in the USING parameter which contains the value of the current iteration of the loop.
Refer to the END_LOOP command for more details and examples.
Also See
BEGIN_LOOP --- USING -------- *INTERNAL ---------------------->
field name
>--- FROM -------- 1 ------------------------------>
numeric value or field name
>--- TO ----------- 9999999 ------------------------>
numeric value or field name
>--- STEP --------- 1 ------------------------------|
non-zero numeric value (+ or -)