Do you know the hostname or domain name you are trying to/need to send to ?
If so, you could possibly add an entry to the C\WINxx\System32\Drivers\etc hosts file. There should be a sample file there which you can edit in Notepad but I doubt this would help as it is for normal DNS.
Reverse DNS would be an unusual service to be using on your PC unless you are running a mail server. For it to work properly your ISP has to know that you are using it.
Other than that I don't have any ideas I'm afraid as it's such a rare one.