How do I know when a user account is about to expire?

Is there a method that will allow us to know when an account password is about to expire?

Is there a way to reset an account password by script or sql?

Here is our problem;

We have a handful of so-called service accounts in Agile.  These are utilized by external processes to access Agile, extract data.

However we have to remind ourselves to catch these accounts before the passwords expire, and reset them.  Otherwise the external processes fail in interesting and (to the end user) alarming ways.

I've been challenged to come up with a way to a) detect when the password expiration for an account is about to expire and b) automate the reset of that accounts password to a pre-determined value.