use Win32::OLE qw(in with);
my ($ex, $book, %WS);

my $Exname="$ENV{USERPROFILE}\\Documents\\ABC.xls";

# Always use a new instance of Excel so as to not interfere with anything open on the desktop

$ex = Win32::OLE->new('Excel.Application', sub {$_[0]->Quit;})
                    or die "Oops, cannot start Excel";
# Set Application Visibility; 0 = Not Visible, 1 = Visible
$ex->{'Visible'} = 0; # 'Not Visible' is the default, but set it anyway

$ex->{DisplayAlerts}=0; 
$book = $ex->Workbooks->Open($Exname); 

$WS{$book->Worksheets(1)->{name}}=$book->Worksheets(1);

#############################
#                           #
#    Work happens here      #
#                           #
#############################

$book->Close;
Win32::OLE->Uninitialize;
undef $book;
undef $ex;

##</code><code>##

use constant xlMinimized => -4140;
$ex->{'WindowState'} = xlMinimized; # the window will be momentarily visible anyway