use strict;
use Win32::OLE qw(in with);
use Win32::OLE::Const 'Microsoft PowerPoint';

my $filename = 'somehtml.html';
my $PptApp  = Win32::OLE->GetActiveObject('PowerPoint.Application')
	    || Win32::OLE->new('PowerPoint.Application', 'Quit'); 
     
  $PptApp->{Visible} = 1;
  my $Presentation = $PptApp->Presentations->Open({Filename=>'somepresentation.ppt',
                                                   ReadOnly=>1});
 
   $Presentation->SaveAs({Filename => $myfilename,
                         FileFormat=> ppSaveAsHTML});