Radius Proxy Accounting

Hi Everyone, I'm trying to setup a FreeRadius server to act as a proxy for another DNS server, and this seems straightforward enough from the documentation, however I also want the FreeRadius proxy to send accounting information to another Radius server. I haven't seen any documentation on how to do this and I'm sure there is a simple way to configure this. Any help or pointers to some documentation would be much appreciated. Best Regards, Jeremy