col1 col2 col3 col4 col5
1234 5678 9012 3456 7890

##</code><code>##

col1 col2 cYl2 col3 col4 col5
1234 5678 5Y78 9012 3456 7890

##</code><code>##

use strict;
use warnings;
my $line;
while($line=<>){
        chomp $line;
        $line =~ s/(.{5})(.{4})(.*)/$1$2 $2$3/;
        $line =~ s/(.{11}).(.*)/$1Y$2/;
        print $line."\n";
}