You can extract a contour (or contours) from a surface in a given elevation range as AutoCAD entities. This example extracts the contours between 90 and 95, and prints out the entity type for each one.
The contours that you wish to extract must be visible in the drawing for this example to work.
... Dim z As Double Dim objSurf As AeccSurface Set objSurf = g_oAeccDoc.Surfaces(0) Dim varObjects As Variant Dim objEnt As AcadEntity Dim iCtr As Integer, iLow As Integer, iHigh As Integer varObjects = objSurf.ExtractContour(aeccDisplayOrientationPlan, aeccSFMajorContours, 90, 95) iLow = LBound(varObjects) iHigh = UBound(varObjects) For iCtr = iLow To iHigh Set objEnt = varObjects(iCtr) Debug.Print TypeName(objEnt) Next iCtr