Hooking up laptop top external monitor

I purchased a Dell XPS L502X laptop and a Dell U2412M monitor.  The monitor came with three cables two of which have ends with pins.  There is no port on the laptop to accept that kind of cable.  I have contacted technical support and the sales dept but must be talking to a bunch of hich school dropouts because I can not get an answer toa simple question.  Am I out of luck in hooking these two items together or is there some kind of an adapter that will make it possible.  I am through with talking with the fools at tech support and sales.  I should have listened to my son and bought an Apple.  Right now I say the Hell with Dell.  Does anyone out there know the answer?