You've already been given all the fancy ways, but I don't see where anyone has shown you the old-fashioned, primitive way.

foreach ( 1 .. 5 ) {
   my $pid = fork() // die "fork() failed: $!";
   if ( $pid ) {
      say "parent just spawned child $pid";
   } else {
      exec "DoThis.exe";
   }
}
[download]

Of course you'll need to set up a signal handler to catch the SIGCHLD events if you want to know when they're all done.

- doug