mail_reverse_dns wrong ptr

Hello everyone,
I've set in WHM under Exim configuration "Send mail from account’s dedicated IP". I can see that the mail_reverse_dns file is populated automatically with all the necessary ips (atleast during the nightly upcp), however the ptr's it gives for the ips are just the domain names for the account.

So if I had for example an account blahdomain.com with dedicated ip 80.80.80.80, then the line in mail_reverse_dns would be: 80.80.80.80: blahdomain.com.

This is ofcourse wrong because the PTR can be whatever, for example mailserver1.blahdomain.com.

Does anyone know why the real PTR isn't given in this file? It is as simple as "host <dedicated_ip>". If no PTR exists, then it should use the accounts domain name.

Is there any way of fooling cPanel to write the real PTR to this file automatically? I hate the idea of making this file immutable... one more thing to remember and update manually.

Also note that I cannot get the PTR's to be in domainname.ext format because the system which the owner of ip addresses uses doesn't allow this. Allowed format is somename.domainname.ext.

Any ideas are welcome