>Using SQL may involve millions of records while there might be least then 10 items in my grid. I want the fastest way to get the same result.

If you have selected the data in the in the grid (a view?) then you should be able to SELECT SUM(nMyField) FROM MyView ...


>Your comment is welcome.
>BTW, it seems that there is no way to sum up a specific grid column with several keystrokes.

Not sure what you mean here. Do you mean keystrokes you make when coding, or keystrokes the user makes?