This one isn't bound to a keypress, it runs in the background and watches for clipboard changes. It collates screen captures from a mainframe terminal, and stitches them side-by-side. I normally do a de-dupe blank columns afterwards. You have to give it a marker (I use __END__) to know when to finish and write the text back to the clipboard.

@rem = '--*-Perl-*--
@echo off
perl -x -S "%~dpnx0" %1 %2 %3 %4 %5 %6 %7 %8 %9
goto endofperl
@rem ';
#!perl
#line 8
use strict;
use warnings;
use Win32::Clipboard;
my $CLIP = Win32::Clipboard();
my $not_finished = 1;
my @data = '';
$CLIP->WaitForChange();

while ( $not_finished ) {
  $CLIP->WaitForChange();
  print "changed\n";
  $_ = $CLIP->GetText;
  s|\x0d\x0a|\x0a|g; # remove MS line-ends
  if ( scalar @data == 0 ) {
      @data = split "\n", $_;
  } else {
      my $line = 0;
      for ( split "\n", $_ ) {
        $data[$line++] .= $_;
    }
  }    
  if ( m|__END__| ) {
      $not_finished = 0;     # Finished after this block!
  }
}
$CLIP->Set(join("\n",@data));

__END__
:endofperl
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