Perhaps something like this:

{
  defined(my $kid = fork) or die "Cannot fork kid: $!";
  unless ($kid) {
    exec "/path/to/ie", "param1", "param2" or die "Cannot exec ie: $!"
+;
  }
}
[download]

If your Tk program runs for a long time, you should "double fork" to make IE the grandkid, and then wait for the kid, or else invoke waitpid from time to time to ensure that the kid process gets reaped occasionally.

-- Randal L. Schwartz, Perl hacker