here is an approach using a few more modules from CPAN. I think it would make it more expandable in the future or readable 6 months from now.

use warnings ;
use strict ;
use File::Copy ;
use Path::Class ; # file(), dir()
use File::Find::Rule ;

my $INDIR  = "C:/output/input";
my $OUTDIR  = "C:/output/input/archive";
my $NEWFLE = "COMBINED.output";
my $COUNT  = 0;

print "[Task started on " . scalar localtime . "]\n";

my $new_file = file( $INDIR, '..', $NEWFLE );

$new_file->touch();
my $FH = $new_file->openw() or die "etc: $!";

my @files = File::Find::Rule->file()->name( qr/.*\.txt/i )->in( $INDIR
+ );

@files = map{ file( $_ ) } @files;

foreach my $file ( @files ) {

  # Skip file if it is in the archive path.  
  my $archive_path = file( $outdir, $file->basename() );

  next if -e $archive_path;

  # Process file
  $COUNT++;  

  my @lines = $file->slurp();

  print $FH $_ for @lines;

  # you have to "stringify" Path::Class objects passed to File::Copy
  move( "$file", "$archive_path" ) or die "Could not move $file to $OU
+TDIR: $!\n";
}
 
$FH->close();


print "\n";
print " Found $COUNT files with data to process \n";
print " Reading all file data into memory \n";
print " ${new_file} generated successfully \n";
print "\n";
print "[Task completed in "; print time - $^T . " seconds] \n" ;
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