Multiple Knock-out Timers On Sheet

I am trying to make a multiple knock-out timer on a spreadsheet, here is the situation. if i had a list of say 50 ish contenders in a game, all listed on a spreadsheet with their name (static) in the first column, their ID number (static) in the second column and the time left after they have been knocked out in the third column.

Each player when Knocked out will remain knocked out for 15 minutes. what i want to be able to do is press a button when a player is knocked out, which begins a 15 minute timer (displayed in third column) which will turn red and bold when the timer drops below 1 minute.

I have been using the guide here How to Insert a Countdown Timer in an Excel Worksheet | eHow.com but i think that will only work for 1 timer.