hey knowledgeable folk!

im 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.

can anyone help me please, im super noob

many thanks in advance!