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

my $wfwi = Win32::OLE->new ('WFWI.WFWIProject');

$wfwi->Open ('C:\installer\delme.wsi');

my $features = $wfwi->Features ();
my $feature = $features->item (0);

$feature->AddFile ('C:\source\helloWorld.txt', 'C:\Program Files\target\helloWorld.txt');

my $result = $wfwi->Save ('C:\installer\delme.wsi');
$result = $wfwi->Compile ('C:\installer\delme.msi');