Use AppleScript and Remote Desktop to set a non-default NetBoot startup disk

The following AppleScript will use Remote Desktop to set a non-default NetBoot image as the startup disk. Make sure to insert your server’s IP Address and the image name…

tell application “Remote Desktop”
set theServer to “192.168.1.8”
set theImage to “10.8.5 NetBoot”
set theComputers to the selection
set theTask to make new set network startup disk task with properties {from server:theServer, mount volume:theImage, restarting:true}
execute theTask on theComputers
end tell

Source: Mac OSX Hints