Updateing formulas
 

I have 3 wrkshts. 1,2 & 3 all of which are masters to be Saved As each week
and are set to be read only. In sheet one I enter data. In sheet 2 there
are formulas to get data from sheet 1 and sheet 3. Sheet 3 has formulas to
get data from sheet 1. When I do a save as, I have to change my formulas.
Is there a way to:
Mastersheet1.xls=enter data and save as linked to Mastersheet2.xls update
data from sheet 1........and so on and so forth. Thanks. Dawn