The defaults terminal command in MacOS X allows you to add/change settings for applications which use the system’s standard XML based preferences file format.
A perfect example of this is adding items to the Dock for a user. Just copy and paste the following commands into a Terminal window (in this example, we’re adding TextEdit to the Dock; change the filepath to whatever application you want to add ):
$ defaults write com.apple.dock persistent-apps -array-add ‘
$ killall Dock
As with any UNIX command, you can extend this into ARD by using the Send UNIX Command. This allows you to make changes to the dock for multiple users at the same time.