Definitely try something, then post.. here is one idea

use strict;
use warnings;

my $launch_time   =  time();
# Do something with $launch_time

# execute external
my $result = qx!/some/program -flags!;
# Check for success

# or

#exec and exit
{ exec ('/some/program') }; print STDERR "couldn't exec program: $!";
# if exec fails, this script continues
$launch_time      = 'LAUNCH_FAILED';
[download]

On *nix try perldoc -q time to see more ideas.