Binh,
Although you probably will not find a post that you can download and that works perfectly without editing, there are few things that might help you out. The link below will bring you to the PTC GPOST Central Resource page. Although this site has not been updated in years (2004-2005), it still has a lot of useful information regarding post processors. There is a link on the bottom of this page titled "PRODUCTION POSTPROCESSORS". This will bring you to a page that has a few dozen downloadable posts. These are a great place to start and you may find one that gets you 90% of the way there. There are also a lot of useful training presentations and other files, so make sure to browse through all of the links.
http://support.ptc.com/cs/cs_26/howto/ncgp4903/ncgp4903.htm
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Dhinesh