use strict;
use warnings;

my @strings = (
   q{asdfgGOATaewrjgn},
   q{ererGOAskjgbrTslkgjnjng},
   q{ccG<!-- comment on status of global geopolitical economics -->OAjgTsvs},
   q{aGO<h3>i hate clowns</h3>ATbbb});

my $needle    = q{GOAT};
my @parts     = split m{}, $needle;
my $notNeedle = qq{[^$needle]*};

my $haystackPatt = q{(} . join($notNeedle, @parts) . q{)};
my $rxHaystack   = qr{$haystackPatt};

my $stuff1 = q{^^^};
my $stuff2 = q{+++};

foreach my $string ( @strings )
{
    print qq{$string\n};
    $string =~ s{$rxHaystack}{$stuff1$1$stuff2};
    print qq{$string\n\n};
}