Hi matur61,

As Michael said it's not so easy attempt to do that kind of stuff with a Nurbs modeler like Moi,
and maybe it doesn't make much sense.

But just in order to give you and idea, I'll show how to achieve something similar in Moi with a couple of great Max Smirnov's scripts.

Here's the link to a video capture of a little test I did Moi : http://take.ms/18mOK

And here's the zip archive containing the stuff that I have used : http://take.ms/25j6J

I have used Moi V3 for Windows and only these commands :

1) HeightMap : Max's script
2) PatternSelection : Max's script
3) Rebuild : standard Moi command
4) Loft : standard Moi command

After extracting the zip archive you will get a "commands" folder and the "height_001.png" file.

Copy the file contained into the "commands" folder into your Moi's "commands" folder.
Put the "height_001.png" file wherever you want.

N.B. If your are a Windows user you need to run Moi in administrator mode in order to use the "HeightMap" script.
Or at least, this is what I need to do with my Moi.

This is just an example and you can play with different pngs or different settings for Rebuold or Loft commands,
or you could try to use also the Network commands instead of loft, but in this case you need to generate both curves (x and y) with the "HeightMap" script.

Have a nice day.