I made my own user on my mac osx and I went to play cod4 on it, and I had to restart the game all over, but on the other account (Which I don't want to play on) has all the stuff on it. On the first user, with all the stuff, I tried to copy it and paste it onto the other user. But it didn't work. Is there anyway I can do this?

Generally copying the program from the Application folder works . Is that what you tried ? Now I assume that you had to restart everything on the other user because u lost all your settings or screenshots that you saved for your game on the previous user account .

For that if you want to transfer your settings and screenshots, you'll need to copy Cod4's application support folder as well. You can find it at:
~/Library/Application Support/Cod4

If you're on OS X Lion or later, the Library folder is hidden by default, so you'll need to get to it by opening Finder, going into the Go menu, selecting Go to Folder, typing in the following:

~/Library/Application Support
And pressing the Go button. Copy the entire Cod4 folder there to your new account, placing it in the same location.