I just finished an OSC plugin for Quartz Composer that allows the user to change the IP, port number and address space dynamically through the input ports.
The current version does not support sending QC Structures as multiple values, but I am looking into ways of implementing it. Please let me know, if you come up with a good solution.
Download the plugin and the soure code.
This plugin uses the VVOSC framework developed by mrRay.