After seeing @BIGAL's suggestion, I'm wondering if I understood correctly what you're asking, Vica.
Anyway, I'm attaching a short clip of what I'm talking about.
FACTVM de ARCTIS.mp4
I’ve implemented a small emulator of the "pline" command in the base code, but each user should implement the code they need for their specific task instead.
Basically, the distance variation from the last stored point in LASTPOINT is displayed above the cursor (though this can be easily changed by modifying the textoGR1 function).
Below the cursor, any desired information about the object under it will be shown (or not, if visibility is toggled by pressing the F10 key). This information must be passed to the textoGR2 function as a list of (Property_Name StringValue) pairs.
The main code must be implemented in the 'FuncionPrincipal' function.