How can you make the RF coverage plot display the signal coverage many feet above ground level?

I'm making a simple RF coverage plot using the Longley-Rice model for the coverage from a dipole antenna, and I'm considering multiple locations to put a mobile antenna tower that is 35 ft above ground level.

I know how to make a link between the TX and the RX when the RX tower is in one location, but i'd like to know what the coverage is for the tower at multiple locations, all at approximately 35' AGL. I'd settle for having a plot for the signal coverage at 35' ASL, since it seems like this would be an easier plot to generate.

Any idea if there is some sort of vertical scaling available for signal coverage? e.g. Here is the coverage at sea level, at 10' ASL, at 20' ASL, and so on.