Insert username from Windows login automatically

[Ernie in Tampa]

I'm creating a powerpoint presentation that will be edited by different users
throughout the day. I would like their username, as shown in windows, to
appear automatically when the presentation is opened. I have a section that
updates the date and time, but haven't been able to find a way to insert
their name without them manually changing it. Can this be done? Thanks in
advance.

Ernie