Projecting (moulding, wrapping) a 2D ceiling plan to a 3D Edge surface

Hi All
The ceiling plan which I am working on is a blown-off. First, its XY plan is very complicated, it consists of many shapes but, what is more difficult is that its Z elevation is changing as well (as the sea surface).
So my problem is how to change the Z-coordinates of my XY ceiling plan to reflect its variation in Z-axis.
I can not find anything straight forward in the text books I have so I ask you for help.
I had an idea to use either VBA or AutoLisp, but I was hoping that those scripts already exist and somebody would be so king to give me such a script.
The script should take two objects, one is the planar XY plan of my ceiling and the other is the XYZ mesh or edge surface and use it to update the Z coordinates of the ceiling plan. The output should be the new XYZ edge surface with updated XYZ points from ceiling plan.
If somebody can help me with this it would be great.
thanks in advance ewa

Hi I think I know what you mean, the easiest way to do this is if you just know the basics about setting the screen ---- you need the viewports command and the useal 4 windows, one with the perspective and the other 3 as top-side and front views. The smart about four screens are that you can go from screen to screen while drawing the lines ,so you can start from top view and that way set what you call the Z value by continue the lines you draw on either the front or side views. If you maneage to fill the area with a mesh you still need a quite fine net and you need to edit many cross points --- now this can also be done as I point out by going from one plane to the next by vindow.

Hi Per Thanks a lot for the answer, but I do not think so it is a solution for me. The reason for that is that my ceiling has around 10000 vertexes (points) which means a lot of manual work to do. If I spend 1sec for each point it is roughly 2 h to do the job, not mentioning the number of mistakes I will surely do.
I think the only way to do that is some kind of automation. My Z-mesh is generated automatically and all (and as much) is to locate the Z-coordinates for each point in the corresponding XY mesh plane and update it with the value of the mesh point.
I have done a simulation in Matlab and it took me 15 min to write a script. The problem is that I do not know the VB or Lisp and I thought that one good man could share it with me.
Thanks anyways take care Ewa

Hi I offcaurse suggest the lines to be drawn as polylines as then ,if you draw sections, most of these rutines that ask "definition lines" will themself calculate the many cross points . Anyway what you ask is not so different from the programs I used for boat design ,there you also need a number of sections --- ribs -- and when you placed the sections you must be able to point out one by one, all the section lines that the program then uses to calculate a much more accurate smoothened surface. But when you have a 3D drawing of the ceiling then what ---- are you then going to generate new sections one to one ,and use these as templates , how will you make use of the drawing make the thing into real ?