Setting up CIDR PTR Zone

[Auteria Wally Winzer Jr.]

I have a /27 that i'm responsible for and need to setup the PTR zone file
accordingly.
The ISP has given the company authoritive control for the CIDR block.
Currently I have a db.204.247.175 file that has PTR RR's from 97-126.  This
uses the regular convention:

97        IN    PTR    hostname.domain.com.

I changed the above line to look like this:

97.96-27.175.247.204        IN    PTR    hostname.domain.com.

Then pointed a CNAME to it:

97        IN    CNAME    97.96-27.175.247.204

When reloading the zone no slave servers picked up the update.
What do I have to do to make this work?
1. Do I need to change the name of the zone file?
2. Should I replace the "-" with a "/"? Or does that matter whatsoever?
What steps need to be taken in order to accomplish this feat?

Thanks a bunch.

Wally Winzer Jr.