I have a speadsheet that forecasts the number of parts built each month for
2007. I would like to replace each months forecasts with actual production
numbers, and then have the speadsheet adjust the remaining months forecasted
numbers accordingly in order to keep the total annual forecast the same.

EX:

FCJan = 100
FCFeb = 80
FCMarch = 120
FCApril = 100
FCMay = 100
FCJune = 70
FCJuly = 130
FCAug = 100
FCSept = 100
FCNov = 150
FCDec = 50
FC2007 = 1200

If actual Jan is 320 then each month thereafter would have to decrease by 20
parts in order to compensate the overproduction in Jan.

Can I create formulas that will still work as I place actual data in each of
the months throughout the year.

Thanks
-Diane