select an area of cells where you need to replace values with values
from cells above

and run this code

:======================

Sub ReplaceWithAbove()

Dim cl As Range

For Each cl In Selection
If cl.Value = "@" Then
cl.Value = cl.Offset(-1, 0).Value
End If
Next cl

End Sub

:======================

As you can see in my code I have had to use @ to switch
You may first have to perform a Find Replace to change all ditto marks
to @

Let us know hope you get on

cheers

somethinglikeant
http://www.excel-ant.co.uk