Sending message when two server users open the same workbook

[SORRY I DIDN'T MEAN SERVER BUT NETWORK ._. ]


Hello,

My question here may be peculiar.

Here is my setup : I have a bunch of Excel workbooks in my work network, and some of them may be opened by a user when another one is still working on it.

MY POINT IS NOT TO MAKE IT SIMULTANEOUSLY MODIFIABLE. It is important and has to be said before anything

What I wish to know is if it's possible to "warn" the person that is already working on the workbook that someone tried to open it.

Is such a thing feasible with Excel ?

Thank you,

François