Change a color of a single cell in excel 07 by using a kitchen timer style time frame.

Excel 07, MS 07, I need to change the color of a single cell in excel, by clicking on it and having a timer run in the background that will actuate a color change, yellow to red, of that cell after a preferred time frame, like 30 min's.  Also I need the time, say 12:35am, to be shown in that cell at the time of the initial click.   
 
Use: someone go’s on break for 30min. I need to insure they return on time, if not the color of a cell changes to red.      
 
A second click on the cell changes it to green if time has not elapsed.  This part is not critical.
 
Anyone up for a challenge? 
 
 
Thanks in advance..
 
Lost in Excel 07
 

To me this sounds like it would be better to do in VBA not VBScript. The two are not the same. Which do you want to actually use?

I really don't have a clue,  but I will look at them..
 
As I said in my introduction:
"Just starting out on your tundra of knowledge and will need some help in VB /excel 07, but more of that later.  Introduction, as a user of MS products, I get myself in more trouble because I think of what I want to do but don't know enough to accomplish my thoughts.    Hope you can/will help me in my wicked ways.. "
 
I don't use VB as much as I have in the past, so I'm losing my grip. Yes on reality and VB.. LOL.. 
 
Thanks..

For most Office automation the first step is to record a macro of any actions that you can. That gives you a starting point for your code.