Application OnTime

I need help with Application.OnTime code. Most of the online examples of code for this application use Now + TimeValue for the ‘earliest time’ definition. In my workbook I have three time values - 'Now', the start time for the event and a countdown timer to the start time.

My macro is simply going to call for a single refresh of web based input data. So I need an OnTime code that is going to trigger the macro at a specific time in the future. In layman’s terms my ‘OnTime’ will be Now + Countdown time because those two times added together will equal the start time of the event.

The whole point of the exercise is to have a fully automatic set up so I do not want to have to manually insert any information. As soon as the workbook is connected I need it to set up a single refresh of the web based input data timed for the start time of the event.

Cross posted http://www.mrexcel.com/forum/showthread.php?t=579552