need help with shell script

I am trying to make a simple script to change an application's info.plist file. The application is called Spacesuit, and I want to add "LSUIElement" with a string of "1". The only problem is i don't know how to use defaults write on a plist that is not in the preferences folder. Basicly what I'm asking is what would be the terminal command to edit the plist of an application on the desktop? Please help me with this.

 

Thanks, I can't believe I didn't think of that. I am used to using defaults write for apple preferences (com.apple.mail, etc.), so I forgot I could enter a file path. Thanks again.