How do I invoke a service using Applescript?

I'm using Circus Ponies NoteBook which doesn't support Applescript methods. It does support creating services that can clip the current selection into a NoteBook page. This allows me to select text and use the context menu to paste the text into a NoteBook page. I'd like to do the exact same thing from an Applescript script. Is there some way in Applescript to get a handle to an existing service, and send it a message?

Automator services can be run with the automator command line utility:

do shell script "automator ~/Library/Services/test.workflow -i input -d variable=value"

I couldn't get it to work with the service used by Circus Ponies NoteBook though.