GetOptions(
   "u|updated:s" => \my $update,
   "x|XMLFile:s" => \my $xmllocation,
   "e|XLSFile:s" => \my $xlsfile,
);
$update or die "...";
$xmllocation or print "blabla";
$xlslocation or print "blablabla";
#And in your routine
system(qq(sjdks $xmlfile)) if $xmlfile;
#dito for $xlsfile