Program a cell to add its contents to another cell
 

I am not familair enough with VBA to figure out how to do this. What I would
like to do is generate five buttons, one for Mon-Fri, and those buttons will
refrence one cell that a user will type the number of hours into. for
instance if the user wanted to add 6 hours to Monday, they would type in 6,
press the Monday button, and another column of five cells would show the
total, and the cell they originally inputed into would return to 0. If they
then later wanted to add five hours to monday, they type 5 into the cell,
press monday, and now a total of 11 hours shows in the additive cell. I
would like there to be an erase values button. On top of this, if at all
possible, it would be easier if the user could click on the cell that
contains the hours from the pivot table, and the value is automatically
inputed into the destination cell that they would otherwise type the hours
into. For instance on the pivot table they would see a selection of hours
they would like to add to monday, so they would click on the 6 cell, then the
monday button, and six hours would be added to monday. I am unsure if that
is possible in a pivot table, so if not, having them type 6 hours in will
have to work. This seems very complicated to me, any ideas? Thanks so much.