Instead of using a keyboard to send hotkeys to gridmove, I have been trying to use an ahk script to do the same.
So far I have working ahk code which launches the gridmove interface successfully as follows:

             ;------------------------------

             Send, #g ; Activate a grid in GridMove

             Sleep, 1000
             ;BlockInput, On

             ;------------------------------

However, I am having trouble with the second part of the command where an actual grid number must be specified:

            ;zone_key_a := "1"
            ;zone_key_b := "0"

            zone_key_a := 1
            zone_key_b := 0

                SetKeyDelay,100
                Send, zone_key_a
                SetKeyDelay,25
                Send, zone_key_b
                SetKeyDelay,100

                ;SetKeyDelay,100
                ;ControlSend, "- -", zone_key_a, "OSD"
                ;SetKeyDelay,25
                ;ControlSend, "- -", zone_key_b, "OSD"
                ;SetKeyDelay,100

                Sleep, 1000

In the above example I have commented out several experiments. For example, I tried to extract the names of GridMove widgets for the ControlSend command. In other cases, I used the Send command instead. I am also wondering if numerical variables which identify a grid by number should be represented as text or as numbers. Thank you in advance for any thoughts which you might wish to contribute.