My fault. I didn't understand the equation. I used the column header as the variable, not "X". When X is used, it works fine. One other thing, with the transformation, the label would be the recalculated height in meters. So, to display the height in feet, I guess it would be easier to have two columns in the spreadsheet, one with meters for z elevation plotting and one in feet for label display. No big deal.

Thanks for the reply and keep up the good work.