SET MATRIX HEIGHT
This command will set the individual height of a point within the matrix. To raise a
whole grid square you would need to raise four points, one from each corner of
the square. If you set points x=0 z=0, x=0 z=1, x=1 z=0 and x=1 z=1 to a value
of 10, you would raise the near left square upwards by ten units. The matrix
number and tile reference values should be integer values. The height value
should be a real number.
SYNTAX
SET MATRIX HEIGHT Matrix Number, TileX, TileZ, Height
Could that be what you are looking for?
RPGamer