They way i would do it is to use applescript "do shell script" save that as a script and then put it in login items.
I don't know how though. You cant just paste the command and expect it to work right? I mean I don't know apple script
EDIT: Tried that, didn't work.
Check out this link. http://www.osxfaq.com/Tutorials/LearningCenter/HowTo/Startup/index.ws
It has everything you need to make the shell script execute on start up without having to mess around with applescript.