can you give some examples of the before and after's of your data? You say "global substitute" but aren't clear on what you're transforming the data into ...

if you are just matching, it looks like all you need is a capture in your regex:

  if (substr($acct_trtmt_hsty,1,1) =~ m/([789])/) {
    print "the number is: " . $1;
  }
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Are you sure the LHS should be the substr and not $acct_trtmt_hsty ? You may also want a strict regex:

  my @numbers = $acct_trtmt_hsty =~ m/'([789])'/g;
  print join ":", @numbers;
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Substitution example (subtracts 4 from every number):

$acct_trtmt_hsty, =~ s/(')([789])(')/$1 . ($2-4) . $3/eg;   # note: ma
+ny different ways to write this regex
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