Reading a global number parameter in python handler

Hi;

I have a gladevcp panel that I would like to display a counter from a gcode routine. In my gcode I have something like lcnt = lcnt + 1 to track the iteration number of a loop. IF I understand the documentation correctly I could assign this value to a global number parameter, say #1000 by using the syntax #1000 = lcnt.  That all seems simple enough.

Now I would like to:
1. Read the contents of #1000 in a python handler associated with the gladevcp panel and display the value on the panel. (I understand the display part, just not the read part)
2. Know when the value of #1000 changes to update the display

Is this possible? How would I code python to read the value? How could I know if the value has been changed by the gcode? Is there an on_changed signal for variable updates?

Kind regards,