I guess I should post this too. This is the little demo I wrote myself
to prove it worked. :)
j
$ cat j.pl
my $apply_this_card_to_all = "new";
my $before = <<EOT;
...xxx...
...xxx...
...xxx...
EOT
my $after = $before;
$after =~ s/(.{3}).{3}(.*?\n)/$1$apply_this_card_to_all$2/gs;
print "$before$after";
$ perl j.pl
...xxx...
...xxx...
...xxx...
...new...
...new...
...new...