use Mac::AppleScript qw(RunAppleScript);
...
sub run_script {
  my $script;
  my $msg = shift;
  ($script = <<"  EOS") =~ s/^\s+//gm;
    tell application "PDFCompressor"
      ... # more applescript here
    end tell
  EOS
  RunAppleScript( $script ) or die "couldn't run applescript - $!";
}