multiple workbooks

[hostelowner]

Hello,
I am new here, I will try and be as clear as possible.

My daily income reports (cash and credit card sales) are wrong because of a single cell value referencing the wrong cells in each worksheet. This would be easy to change, but I have years of sales and would need to open each day and change this value one by one.

The way I have my files organized is straight forwards.
DIR= HOSTEL/SALES/2012/Jan/1.1.2012.
1.2.2012...etc 1.31.2012

DIR= HOSTEL/SALES/2012/feb/1.2.2012....etc 1.28.2012

I want to correct the cell to ref the right data for every excel file
1.1.2012 to 1.31.2012 jan
all months
all years

Formula
Particular cell "=E46" that needs its value changed to hold the correct value "=SUM(E8+J8+E28)". The worksheet is titled "control caja" and its always the same title sheet across all/mulitple workbooks. Each workbook is titled after a date, eg: 1.1.2012 etc... These workbooks are excel, and each one, represents sales for the day.

Want I want to do is do a one time update of this formula for all my files I have saved so i can and work off correct data on future templates.
thanks for your patiance

regards
mark