Aqui está um par de macros para fornecer a funcionalidade desejada:
Sub RemoveFormulas()
For Each r In ActiveSheet.UsedRange.Cells.SpecialCells(xlCellTypeFormulas)
r.Value = Replace(r.Formula, "=", "'@")
Next r
End Sub
Sub RestoreFormulas()
Dim r As Range
For Each r In ActiveSheet.UsedRange.Cells.SpecialCells(xlCellTypeConstants)
If r.PrefixCharacter = "'" Then
r.Formula = Replace(r.Value, "'@", "=")
End If
Next r
End Sub