I agree with the above posts ... just tell the agent to tag them to AMS so you can (...make up your own reason here...) and that youŽll recheck them to DUS from there.

Then to be sure look at the tag they put on your bags and make sure you see a big "AMS". If you see "DUS " donŽt let them go down the belt because theyŽll be on their way to DUS.