This is an AutoHotkey script that will periodically check for the existance of a particular window, and click once at the requested coordinates.
By default, this will check every few seconds for a pop-up with the class of "Campaign Manager" and click at the (approx.) coordinates of the "Remind me later" button. The coordinates will vary by screen size, so you will need to enter coordinates for your own monitor.
(requires AutoHotkey v1.1.37.02 or greater to compile)