Incrementing numbers in REXX

Question

I have a requirement where I take a SUBSTR (e.g st_detail = "%BOM0007992739871P", st_digit = SUBSTR(st_detail, 8, 10) ). I have to do some validations on the st_digit and if it is valid change "%BOM0002562186P" to "%BOM0002562186C". My code works fine upto this. But I was asked to increment st_digit (I used st_digit = st_digit + 1 ) and print 100 valid st_digits and append it with C. so I put the code in a loop and display st_detail. But when i ran it i got "%BOM0007.99273987E+9C" after first increment. Please help on how to display "%BOM0007992739872C"? (NOTE: this is a reference only and I can't display the validation logic here and my code works fine. The extra code i added was the code I used here)

out_ctr = 1
DO while out_ctr < 101
   /* validations */
   IF valid THEN
     say st_digit " is valid"
   ELSE
     say st_digit " is invalid"
   st_digit = st_digit + 1
   out_ctr = out_ctr + 1
END

Answer 1

It seems the NUMERIC setting was " 9 0 SCIENTIFIC ". I changed it to NUMERIC DIGITS 12, So, now it works.

parse numeric my_numeric_settings
say my_numeric_settings   /* 9 0 SCIENTIFIC */
NUMERIC DIGITS 16
parse numeric my_numeric_settings
say my_numeric_settings  /* 16 0 SCIENTIFIC */

It's because I used SUBSTR(st_detail, 8, 10),So, st_digit is of length 10, which is greater than the DEFAULT setting of "9 0 SCIENTIFIC", So by changing it to either "NUMERIC DIGITS 10" or "NUMERIC DIGITS 12" the code worked.