use strict;
use warnings;
use Win32::OLE;

my $xl = Win32::OLE->new('Excel.Application');
$xl->{Visible} = 1;
my $wb = $xl->Workbooks->Add;
if ($wb->Sheets->{Count} > 1) {
	for (2..$wb->Sheets->{Count}) {
		$wb->Sheets(2)->Delete;
	}
}

$xl->VBE->ActiveVBProject->VBComponents->Add(1);

my $cm = $xl->VBE->ActiveVBProject->VBComponents(3)->CodeModule;
my $line = int($cm->CountOfLines);
$cm->InsertLines(++$line,"Function Example(n as double) as double");
$cm->InsertLines(++$line,"Example = n^2");
$cm->InsertLines(++$line,"End Function");

my $sht = $wb->Sheets(1);
$sht->Range("A1")->{Formula} = "=Example(2)";
$sht->Range("A2")->{Formula} = "=2*2";

my $a1 = $sht->Range("A1")->{Value};
my $a2 = $sht->Range("A2")->{Value};

if ($a1 != 4 or $a2 != 4) {print "We've had a problem"} else {print "Life is good"};