Controlling Individual Volumes in EASTWEST Silver Plugin

In Logic Pro 7, how can I get the mod wheel to control the volume of individual instruments within the EASTWEST Silver plugin? Right now I'm having to create multiple instances of the plugin for each instrument. Would like to get away from that (obviously). I see there is a controller assignments page under Preferences/Control Surfaces, but I don't understand how it works.

Message was edited by: Gary Driskell