Help to end my frustration! Please!

I am trying to work with the expiration feature in AutoPlay 3.0. I understand that I need to set the security feature to the number of days I would like, and I also understand how to make the setup.exe not run after that date, BUT, how could I:

1) Advise the user how many days are left, I uhave tried the message feature, but am unclear on how I can set a variable based on an equation such as %myexpiredate%-%date% or something like this?

2) Require a new password after my setup expires that will reset the expiration date?

Is this possible? Can someone help?