How can I start a video take

Hi!

There's an application protected by showing meaningless stuff during
my short absence, while the Acer Aspire One keeps running. After a
click on an icon it shows all the rest, again, provided one knows the
password.

I'm certain that trials will be made to have a look at secret data
during my absence since the interested people ar pupils. They have
nothing sinister in mind, but they love to tamper with what isn't
theirs and to explore the unknown - thus the best pupils you can
think of.

It is impossible to crack the password within the few minutes I might
be elsewhere, but nevertheless I'd like to show a film to the culprit
trying to find out what is not his business. The Aspire One has a
built-in camera which makes ist possible.

The application mentioned is an Excel workbook for school form
administration, enhanced by much VBA code. It would be easy to start
a video take from within VBA as somebody fumbles with the respective
button.

So this is my problem: How can I start a video take secretly, i.e.
which are the start-up parameters for running the video application
in minimized mode, immediately recording, if possible limited to a
duration of, say, 10 seconds or so?

Sorry for my English.

--
Tschüs!

Arnulf