Updating the Sum of a cell
 

The problem I have is we are tracking the total hours worked for a two week
period. Some of the employee's work overtime and choose to recieve comp time
rather than the extra pay. We are trying to track the accumulation of the
comp time earned. I thought that I could update the "Sum" cell but can't
figure how to add a value to it without having a bound cell for the entry.
The other part of this data will be to support a manning requirement document
in the future.