Re^2: Replacing a specfied instance of a pattern in a string

[GrandFather]

or to pass the index in use:

use warnings;
use strict;

my $foo = 'Fsih my test variable is fsihd or is it gfsih or gfsihd fsi
+h';
my $i = 2; # Replace the 3rd
$foo =~ s/((?:fsih.*?){$i})fsih/$1fish/i or warn "Not found";
print "Foo = $foo\n";