I have 3 data cells which I would like to link in logical way. They are:
"GOAL"
"ACTUAL"
"DAYS LEFT"

It is about the performance of the people in a call center. The way that it works is that montly goal is divided by the numbers of days left and we get the daily goal, named "GOAL" above. When somebody's ACTUAL is lower then his/her GOAL, then on the next day his/her GOAL is going up.
For instance:
GOAL Actual Days left: 22
Monday: 10 8
Tuesday: 12 10
Wednesday: 14 14

Now, the days left is 22, when I click in any of the Monday's row cell. I would like it to change to 21 when I click in any of Tuesdays row cells and to 20 when I click to any of the Wednesdays row cells.

Any suggestions to solve my prob ?