How do I reference a cell to automatically update in a header

[Dan]

How do I reference a cell in a worksheet to automatically report in a header
or a footer.

 

[מיכ×ל (מיקי) ×בידן]

I believe it could be accomplished with an Event-Macro at the sheets level.
Assuming B5 Text should be reflected as the Header - try this:
------------------------------------------------------------
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$5" Then
ActiveSheet.PageSetup.CenterHeader = [B5]
End If
End Sub