Jos,

It rather depends on what you have in mind. The best thing I can think of
would be a modeless form that is running but not visible with a timer
control running at periodic intervals, but this is not trivial and you would
have to be careful about what you put in the routine. You also have to be in
XL2000 or higher since modeless forms aren't possible in XL97. For an
example that you could adapt, have a look at my VBA timer activex control
he

http://www.enhanceddatasystems.com/E...ExcelTimer.htm

Other approaches would be to
use the OnTime method, although I find this horribly crude and if it fails
once because the user is editing a cell it will not run again,
or look at using the Windows timer APIs and callbacks.

Robin Hammond
www.enhanceddatasystems.com

"Jos Vens" wrote in message
...
Hi,

is it possible to let excel do things in background (and let the user work
when the task is running). I'm thinking of the idle time a user is
starring at his screen and then, I could open a sheet in background
(hidden window). When he/she clicks on a button, making the sheet visible
would be much faster than opening the sheet at that time.

So, I want the user let work when my background task is running (slower is
not a problem).

Thanks,
Jos Vens