How do I create a reverse DNS lookup PTR record

I used zoneedit to create RDNS records for my IP address block and it worked great.  It was just a pain to get it setup.  
We created a record in ZoneEdit.  The IP block has to be formatted as such: XX.XXX.XXX.XXX-XX where the -XX represents the subnet masks /29 for example.  After ZoneEdit assigned us name servers we had to send a request back to ATT (our T1 provider).  The email basically told ATT to change the nameservers for our IP block.
"We are requesting a change for reverse DNS zone delegation.
Please change the DNS servers for DSE IP block XX.XXX.XXX.XXX-XX on Circuit ID DHEC-XXXXXX to:
ns12.zoneedit.com
ns14.zoneedit.com"

This is the help section for RDNS on ZoneEdit's website
How do I set up reverse DNS?
If you have an entire class C netblock, and your ISP will delegate reverse DNS to zoneedit, then you can do the following:
First, you need to add the ARPA zone to the zoneedit system (example: 3.2.1.in-addr.arpa.)
Then you need to tell your ISP (or ARIN) to delegate control over that zone to the nameservers assigned to you
For these sorts of zones, there's no need to add A records, only PTR records are needed.
Example of a PTR: 4.3.2.1.in-addr.arpa. IN PTR www.mysite.com
We also can support CNAMEs to serve PTR records from our servers, so you can control less than a whole netblock
You should not delegate a single IP address using NS records. This may work, but it will be unreliable.
Reverse DNS is hard, especially because of the preponderance of virtual web servers. 9 times out of 10, you should simply get your ISP to set up a reverse DNS record for you, rather than trying to get a CNAME or an NS delegation.
Reverse DNS is not required for the correct operation of web servers and most other internet systems.

Hope this helps