In order to use grid's DblClick event you would have to put code in Column's text DblClick event like this.parent.parent.DblClick(this)

In grid's DblClick you can do:
lparameter toTextBox && not really needed, but just in case
this.KeyValue = evaluate(this.ColumnHidden.ControlSource)

where you grid would have a custom property KeyValue and your hidden column always would have some predefined name...

>I am building a customer lookup grid in VFP8 that includes a hidden column that contains the customer's PK. I want the grid double-click event to return the PK of the selected row to the calling program.
>
>I am trying to use the grid's Valid event to store the PK but have had no success with this technique.
>
>Thanks,
>Tom Hall