Triggering a Disconnect-Request

I know I can use radclient to send a disconnect message to a NAS. Is there any way to trigger the FreeRADIUS process to send a disconnect message instead? In my case, I have a FreeRADIUS server running happily, and an external script that sends disconnects. Right now, the script runs alongside FreeRADIUS on the same server. I would like to move that script elsewhere, but I would like to offload it to another server. Problem is, the NAS only honors requests from known RADIUS servers. If it receives the request from anywhere else, it is simply ignored. Ideally, my script would send some sort of message (something like a status message) that FreeRADIUS would turn around into a disconnect request. Any ideas? Thanks Norman