Thank you for that. I didn't know about the "return 5" bit. 

But more than putting TO the OS X clipboard, I'm confused trying to get FROM
it. Like if I send a two line clipboard, such as:
hscript
www.google.com
and what I want is for Applescript to act if it sees my "hscript" flag is
the first line (indicating I want it to do something with this clipboard). 

I would like it to do the following:
- see the flag
- take the URL and open it with a browser
- clear the flag part of the clipboard (so it won't repeat itself)

Later on I could create other types of flags for other things (like sending
simple Applescripts from the emulator)