Automatically show dimensions within/without a range

gilesg

Hi there,
I used 0.5m contours to grid a surface containing an earth embankment.  I'm wanting global mapper to highlight areas of the embankment where the crest is less than a certain value as to it's horizontal width.  I've checked with the sectioning tool and a nice level crest has been interpolated by the surface model.
Any ideas how I could do this?  
Thanks,
Giles.