Mastercam comes with many many posts on the CD. I've seen one that starts with MPBos, see if you can find it on the CD. If not, ask your reseller for it. When you get it, post some code with it, then come back and maybe we can walk you thru making the mods yourself. (I'm sure it's just a switch you need to toggle inside the post to enable 4th axis.)
p.s. Asking someone to give you a post will usually get you ignored, or flamed. Most MC users modify their own posts, or pay to have them developed, so asking for 'freebies' is a no-no. Keep in mind that while they won't just give you a post, they'd be more than happy to help you with yours..
'Rekd