I wrote something like that for external apps to pass data into Poser. I have a server running on a tcp/ip socket bound to the loopback (lo) interface.
http://www.renderosity.com/messages.ez?ForumID=12390&Form.ShowMessage=2022288

Currently it accepts filenames, then it loads (or executes .py files) them. Seno Software (P3dO) has a plug in comming out for it soon.

Next step is for it to accept a input stream so we can do RPC or accept arbitrary data (need to define a protocol).

My main problem is how to run my server daemon in the background, Poser's python doesn't have threads. I have to run a Tkinter instance.
Did you find a way around this using the python that ships with Poser?