Finding the average of multiple values from one cell that are separated by commas

Hello,
I have been asked to find a way to average values that have been entered previously into excel. These are whole, positive numbers in one cell, grouped in threes and separated by commas (example: 7574, 7728, 6849). Is there a function or formula that can output the average of these numbers into the adjacent cell? Pretty much starting over with programming language, it's been since the 80's since any computer science classes, so I may seem a little dense when it comes to making this work. Please bear with me, and thanks in advance for the help!
UPDATE: I've just been informed that there will be no adjacent cell to output the results, I may need to return the value to the same cell. Is this possible? I have to do this with two or three adjacent columns of values and do have one column open to the right of these. I may need a way to display the results of the averages of each cell together into the one open cell. These things always sound so simple until you say you'll try to help! Thanks again!
-Dave