Stop links changing when I use SaveAs to create a backup

I have two spreadsheets that are linked in Excel 2007. They both hold very different information about the same projects, so each row shares some information. However, they are both very large and I do not want to combine them in case the whole spreadsheet becomes unusable. I'm not allowed to use a database

When I save Spreadsheet 1 in a different location, so that I have a backup of the precious data, the link in Spreadsheet 2 changes to show that new location. I want the link to stay at the old location.

Is there a way to stop the link changing when I use SaveAs, so that when I open Spreadsheet 2 it refers to the original location of Spreadsheet 1?

Thanks

Jo

Thanks newdoverman. I will take your advice to heart.