Its impossible from "Azeroth" map ID assuming your talking about Kalimdor, EK, or Northrend. Now above EK, once you enter the portal you will be inside BC content aka Map ID. BC areas are spread far from each other, so that you cannot see it looking out into the horizon. Although, hacks can do the job but if you really want an exploit to do it, simply d/c right before your FP leaves the BC content which is located above EK. Once logged back in, your flight path will skip the port and fly you into the burning crusade area and you will be able to see on your map that you are in fact flying closer to your destination.
You have been edumakated.