I was going to refer to the cpearson site also - a good starting point. It
shows a method to simply start a cell blinking when the workbook is opened.
To do it 'intelligently' based on the value of a cell, you'll probably need
to use a couple of worksheet event processing routines. You would at least
need to use _Change to detect when the cell entered the 'hot zone' for the
value to cause blinking, and to stop it from blinking when the value goes
outside of the zone. Also, you'd probably want to use the
Worksheet_Activate() event to check and see if you need to start the cell's
blinking when someone selects the sheet. Along with that last, I'd probably
add some code to the _Deactivate() event to turn off the blink while no one
is looking at the sheet and not waste CPU cycles blinking a cell that no one
is looking at.
