To determine the z values for specified coordinates follow the next steps:

    1. Load the data set and create any contour map.

    2. Click the item "Points" by right mouse button in the left window and
choose the command "Load new series" from the context menu. Load your specified  points from the file as SERIES2

    3. Double click the item "Data points" for SERIES2.

    4. In the dialog "Data points" press the button "Estimate" and then the "Save" one.