Hi p45cal.

The background of the process is as following:

1.- Click in one cell.
2.- Put "=SUM(" to create a SUM.
3.- Select a range to sum with mouse.
4.- Getting the selected range in an Interop property to send to another application.
5.- Hit ENTER to save the data

In other forum, Hans Vogelaar tell me that object model can not expose data in edit mode. This could be the problem.

TIA.