Help in substring function

[Tom]

 If the maximum number you actually have is smaller than the maximum possible integer that SAS can represent exactly;

586   data _null_;
587     x=constant('exactint');
588     put x= comma23.;
589   run;

x=9,007,199,254,740,992

Then you can just read the digits into a number and put it back out as a string.

id1=put(input(substr(id,4),20.),20.-l);

But if you really have 20 decimal digits then that is too long to put into a number.  So instead using the VERIFY() funciton to find the location of the first non-zero digit.  Let's try both for some dummy data.

data want;
  input id $23.;
  id2=substr(id,4);
  if verify(trim(id2),'0') then id2=substr(id2,verify(id2,'0'));
  else id2='0';
  id3=put(input(substr(id,4),20.),20.-l);
  match=(id2=id3);
cards;
ABC00000012360948952321
ABC00000000000948902321
ABC00000000025369214558
ABC00000000000000000000
ABC12345678901234567890
;