All gurus,
until now I open an excel sheet before the macro read from it, or create an
excel sheet before the macro write to it as follows:

Workbooks.Open FileName:=MyFileName
Sheets(MySheet).Select
(read from the sheet......)

or

Workbooks.Add
(write to it ......)

This way I see each sheet opened or created, a cell is written, ......
(Maybe this causes the macro running very slowly?)
Is it possible to read from or write to an excel sheet without displaying it
in the excel window? Just as, if we open a text file and do reading or
writing, we don't need to open it with notepad. Everything is done in the
background.
Many thanks in advance!

w.wang