Setting up the warranty?
Are you needing a warranty replacement or are you trying to "get it ready" so it can do an RMA in the future?
If its the latter, don't worry - so long as you have the original box (you will need the Works Order Number), the monitor (with its serial number) and the company name of the reseller then you have all the info you need.
On the other hand - did you opt for an extended warranty direct from dell and that is what you are having issues with?
If you do have any issues and provide the above information when needed - they will have a replacement monitor to your door in a day or two.