use Digest::MD5 qw(md5_hex);

...

my $fileMd5 = md5_hex($text) . $ext;

##</code><code>##

open(my $fh, ">", $fileMd5) or warn("Could not create ($fileMd5)\n"), next;

##</code><code>##

if(system(mozilla => -remote => 'ping()')) {
	warn "mozilla not found!";
	my $pid = fork;
	die "Couldn't fork: $!" if not defined $pid;
	exec { 'mozilla' } 'mozilla' if $pid == 0;
}

# and changing the command like so:
# (obviously, use "new-window" if you prefer that)

my $commandShow = q{mozilla -remote "openurl(%s, new-tab)"};

##</code><code>##

Win32::Process::Create(
	my $process,
	 "mozilla.exe", # maybe needs absolute path, dunno
	"",
	0,
	NORMAL_PRIORITY_CLASS,
	"."
) || die ErrorReport() if system(mozilla => -remote => 'ping()');