What happens when you try? Of course if you try accessing "mapped
drives", you will have to fix that issue too.

The task scheduler will log itself in to whatever account you specify when
you set up the schedule. You must also provide the password. When you change
that account's password, remember to update the task scheduler!

Theoretically - yes.
Practically - I doubt whether you can get this to work reliably.
Macros tend to have a big problem: If something is not quite
the way you expect it to be then the macro will fail. It will either
pause and wait for your input, or it will produce garbage. If
you want a robust show then you must perform the calculation
with a language such as VB Script (which has an Excel interface).