use Win32::OLE;
use Win32::OLE::Const 'Microsoft Word';
use strict;
my $File1 = "D:\\Copyfrom1.doc";
my $File2   = "D:\\copyfrom2.doc";

my $Word = new Win32::OLE 'Word.Application', 'Quit';
$Word->{'Visible'}=1;
$Word->Documents->open( $File1)
  or die "Unable to open $File1", Win32::OLE->LastError();
$sep = "\n\n\nxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\n\n\n";
my $text = $Word->ActiveDocument->Content->InsertAfter({Text => $sep});
$text = $Word->ActiveDocument->Content->Text;
$Word->ActiveDocument->Close;

$Word->Documents->open( $File2)
  or die "Unable to open $File2", Win32::OLE->LastError();
$Word->ActiveDocument->Content->InsertBefore({ Text => $text });
$Word->ActiveDocument->SaveAs('D:\\Merge.doc');
$Word->ActiveDocument->Close;