Going on your figures you will need to set your mesh height to around 2500 so the base is lower than your lowest spot level.
Add the contours to the mesh and when you set the height for each contour (or spot level) make sure you set the height relative to your AHD.
Then you just need to type in the actual level - i.e. 38000 for the 38.0 contour.
See attached image but ignore the heights I used (just testing it myself).
Barry.
One of the forum moderators.
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