Entering a Remote Desktop password with Applescript

At the college I go to, we use a lab full of Macs as our music technology lab, and these are all administrated from one computer off to the side. I would like to write a series of Applescripts so that, for example, dragging a file into a folder on the desktop will copy those files out to the desktop of the entire lab. We’re using Remote Desktop 3 to administrate the machines, and I was planning on using that to do the copying and other work. The problem I’m having is that we have a password set on Remote Desktop to prevent unauthorized users from potentially damaging the lab.

What I’m looking for is a way to type a password into a dialog box waiting on the rearmost application. I tried using keystroke like so:

tell application "System Events" to tell process "Remote Desktop" to keystroke "ourPassword" & return
	

However, it doesn’t work and I can’t figure out why. When Applescript opens Remote Desktop, it loads as the rearmost application (i.e., the last app on the Command+Tab list), if that helps any. I’m also not sure where in the chain to put that bit of script. One of the scripts that I’m working on is shown below, and I’ve tried the line above in a number of places.

tell application "Remote Desktop"
	--Choose a list of computers
	set music218 to computer list "Music218 to be cleaned"
	--Assign a screen lock message
	set lockMessage to "Please wait.  Performing scheduled maintenance" as Unicode text
	--Assign some Unix script to a variable
	set theScript to "open -a \"maintenance\""
	
	--Set up a task to lock the screens
	set lockTask to make new lock screen task with properties {name:"Lock Music218", message:lockMessage}
	--Lock the screen
	execute lockTask on music218
	
	--Set up a Unix task
	set clearDesktops to make new send unix command task with properties {name:"Clear Desktops", showing output:false, script:theScript}
	--Execute the Unix task
	execute clearDesktops on music218
	
	--Unlock the screens
	execute (make new unlock screen task) on music218
	
end tell

Also, if Remote Desktop is already open, the script works fine, so that’s not part of the problem.