Suche Powerpoint Formatwandler zu Widescreen

$files = gci "C:\Ordner\*.ppt[mx]"  
$pp = new-object -Com "PowerPoint.Application"  
$files | %{
    $doc = $pp.Presentations.Open($_.Fullname)
    $doc.PageSetup.SlideSize = 15
    $doc.slides | %{
        $_.Shapes |?{$_.Type -eq 13} | %{$_.LockAspectRatio = -1;$_.ScaleHeight(2,-1,0);$_.ScaleHeight(0.5,0,0)}
        $_.Shapes |?{$_.Type -eq 6} | %{
            $_.GroupItems | ?{$_.Type -eq 13} | %{$_.LockAspectRatio = -1;$_.ScaleHeight(2,-1,0);$_.ScaleHeight(0.5,0,0)}
        }
    }
    $doc.Save()
    $doc.Close()
}