use strict;
use Win32::OLE qw(in with);
  use Win32::OLE::Const 'Microsoft PowerPoint';
#Must Be capitalized to load constants--^

my $PptApp  = Win32::OLE->GetActiveObject('PowerPoint.Application')|| 
              Win32::OLE->new('PowerPoint.Application', 'Quit'); 

$PptApp->{Visible} = 1;
  my $Presentation = $PptApp->Presentations->Open({FileName=>'<SOMEFILENAME>',ReadOnly=>1});