Here are some improvements I would make:

• use warnings; use strict;
• Use lexical filehandles $fh.
• Use the 3-argument form of open
• Check the return value of open with die
• Check for 'Debit' immediately
• Use eq instead of a regex to check for 'Debit'
• Just grab the 7th element from the array returned by split
• Eliminate most of those concatenation operators
• close the file

use strict;
use warnings;
use File::Glob;
my @files = glob("C:/Wire/*.csv");
for my $file (@files) {
   open my $fh, '<', $file or die "can not open file $file: $!";
   while (<$fh>) {
      next if (substr($_,0,5) eq 'Debit');
      my $row6 = (split /,/)[6];
      print "{1100}02P N", $row6, "{1110}{1120}{1510}{1520}{3320}{3400
+}{3600}{4320}{5000}\n";
   }
   close $fh;
}
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