Perspective transform in material editor

This is possible to accomplish. However it is very difficult to generate on the fly. You can create a custom UV to create that perspective in some external program, but that would be a static UV.

I suggest you buy the FX and UI Functions pack, its very cheap and comes with lots of new custom material functions. Specifically it comes with a great Perspective Function that you can use to make UVs on the fly to do this.