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

my $Excel=Win32::OLE->new('Excel.Application');
$Excel->{Visible}=1;
$Excel->{DisplayAlerts}=0;
my $Book = $Excel->Workbooks->Open("F:\\assess\\assessment.xls") or die "Can't open file"; 
$Book->SaveAs({Filename        => "F:\\Assess\\Assessment.csv", 
               FileFormat      => 6, #xlCSV, 
               CreateBackup    => 0});
$Excel->Quit;