Modifying AVPs when acting as a proxy

Hello, I have a problem with my NAS and my current RADIUS server. The RADIUS server is responding with 2 vendor-specific AVPs, which my NAS is not able to understand. However, there are corresponding vendor-specific AVPs in my NAS as well. Could I install FreeRADIUS as a proxy between my current NAS and RADIUS server and have it somehow modify the answer I get from my current RADIUS, effectively acting as a translator between my two current nodes? Cheers, -olli