my $xl = Win32::OLE::Const->Load("Microsoft Excel");
    printf "Excel type library contains %d constants:\n", scalar keys %$xl;
    foreach my $Key (sort keys %$xl) {
        if ($Key eq "xlCalculationManual" || $Key eq "xlCalculationAutomatic" ){
            print "$Key = $xl->{$Key}\n";
        }
    }

##</code><code>##

Excel type library contains 2177 constants:
xlCalculationAutomatic = -4105
xlCalculationManual = -4135

##</code><code>##

use strict;
use Win32::OLE;
use Win32::OLE::Const 'Microsoft Word';
use Win32::OLE::Const 'Microsoft Excel';

my $xl = Win32::OLE::Const->Load("Microsoft Excel");      
my $excel = Win32::OLE->CreateObject('Excel.Application') || die $!;
$excel->{DisplayAlerts}=0;
$excel->{Calculation}=-4135;