That doesn't work, suppose I have the string "abacab" and want to replace the second a with an upper case A. Your regex doesn't match. How about this (untested): 
#!/usr/bin/perl -w

use strict;

my $string = "abacab";
print "$string\n";

my $pattern = "a";
my $better = "A";
my $n=1;
my $i=0;

$string =~ s/($pattern)/$i == $n ? $better : $1; i++/ge;

print "$string\n"

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Nuance

In reply to RE: RE: Selective substitution: not in Perl? by nuance
in thread Selective substitution: not in Perl? by Anonymous Monk

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