301 Redirect using windows

[helpme]

I have been trying to set up a 301 redirect, here's the kicker, I'm using windows! I have found several places that give me the code, but don't tell me where to put it. I only want to change the redirect so mommyandbabyessentials.com redirects to www.mommyandbabyessentials.com

This is the code I have found, can anyone tell me what file to put it in and where to put it? I tried tpl_main_page.php and it worked but I then got several errors.

<?
Header( "HTTP/1.1 301 Moved Permanently" );
Header( "Location: http://www.new-url.com" );
?>

Thanks!