Converting 2D Drawings to 3D

I have a number of 2D Autocad Topographical Survey Drawings that require
converting into 3D so that they can be imported into a Ground Modelling
Package and enable cut/fill calculations to be carried out.
In order to speed up this exercise I am looking for an Autolisp routine that
will move "Spot Heights" on the survey drawings to their correct Z value
without having to re-type the value.
Is it possible to do this with Autolisp ?
Each "Spot Height" consists of a point (or simple block) and a short piece
of text giving the value of the spot height. Ideally the lisp routine would
allow selection of each point (or block) together with the text, and then
move them both to the Z value depicted by the text. The X and Y values of
the point (or block) and the text should remain unchanged.
Any help would be appreciated.