MegunoLink

This seems like a very basic question.
In an arduino program, how can I read a value directly from a control in an interface panel?

i.e. the arduino sends the command and gets the value.

All the examples I've seen show how to send or get data from the arduino program, with the command initiated by the user interface control.
That's not what I'm looking for. I want the arduino program to initiate the command to get data from the interface panel.

Any guidance on this basic question would be appreciated.

Regards,
Colin

It's ok now. I finally worked it out.

Great job!