Extrude 2D mesh into 3D with non-uniform z-coordinate?

I apologize if this has been documented somewhere since it may be a popular feature. But I quickly browsed through tutorials and FAQ and couldn't find an answer.

Is it possible to extrude 2D mesh into 3D with non-uniform z-coordinate? For example I have a 2D domain of ice-sheet and would like to extrude it into 3D with varying surface and base coordinate on the z dimension. Please advise.

Thank you!

Cheers, Qiang