I've got a question which is indirectly related to excel.and XP

A friend of mine is accountant. She uses excel on daily basis. I\ll try to explain what she's done.

Let imagine she has a folder in My Document named as January. There is an excel file named as January as well In the folder.

She copied this file onto desktop and renamed it on February.xls and changed all data inside. But when she opened January.xls all data were the same with February.xls. (She overwritten all in January.xls).

I did check what she'd done, and turned out that she created shortcut of January.xls on the desktop.

After changing she saved this workbook.
Now she asks me to bring all data back in January.xls. I told that it's impossible, because you created shortcut of January.xls and changed it and original file had been changen as well.

Now I ask you to tell me. Is here any way to return data back. I'm thinking System Restore, but I don't sure she has created system restore point for yesterday, and not sure that system restore can resolve this issue at all.

So What to do. Is it really impossible....???