Here is the description of the event and its parameters (you are working with batches, right?):
Symbol BeforeDoubleClick Event
Member of PIBTPB.BatchGantt, PIBTPB.BatchGroup, PIBTPB.BatchTrend.
The Symbol.BeforeDoubleClick event executes when you double-click on a symbol.
Private Sub Symbol_BeforeDoubleClick(CancelDefault, ByVal varX, ByVal varY)
Boolean. Indicates whether or not to continue the processing that follows double-click. True will cancel the action.
Long. The mouse pointer's X position at the point where the mouse was clicked. The position is given in logical display coordinates.
Long. The mouse pointer's Y position at the point where the mouse was clicked. The position is given in logical display coordinates.
Yes it is accepting.