How can I compare a set of point features loaded via a txt file to a DEM file.

AlanBullock

Require the height difference between each point and the DEM 

946

Hi,
In case the Z value in your txt file has the attribute ELEVATION, rename it.
Select all the points in your txt file and with the right click go to Analysis/Measurement--Apply Elevation From Terrain Layers to Selected Feature(s).
This will create another attribute (ELEVATION) that represent the Z of each point projected on your DEM.
Than go to Control Center, select the txt file layer, right click and use the CALC ATTR tool.
in the next window create a new attribute like DZ...or something and than substract the txt z from the new DEM z.