What are you wanting to reference?
There are ways to include your reference in text, such as "Today is [DATE]" and have the date pulling from another cell or there is a simple reference where you just want the exact thing from another cell to apprear in a different cell.
You can use this in the BeforePrint event:
ActiveSheet.PageSetup.CenterHeader = ActiveSheet.Range("A1") & " " & ActiveSheet.Range("B1")
HTH,
Private Sub Workbook_BeforePrint(Cancel As Boolean)
If ActiveSheet.Name = "Sheet1" Then ActiveSheet.PageSetup.CenterHeader = ActiveSheet.Range("A1") & " " & ActiveSheet.Range("B1")
End Sub