Search for specific name header column - excel

Question

How can I Search for specific name header column "DATA/HORA" and adapt to macro below?
Sub Data()
Dim cell As Range
Dim lastRow As Long
lastRow = Range("A" & Rows.Count).End(xlUp).Row
For Each cell In Range("A1:A" & lastRow)
If InStr(cell.Value, "-") <> 0 Then
cell.Value = RegexReplace(cell.Value, _
"(\d{4})\-(\d{2})\-(\d{2})", "$3/$2/$1")
End If
cell.NumberFormat = "dd/mm/yyyy;#"
Next
End Sub
Function RegexReplace
------
End Function

Answer 1

Replace:
lastRow = Range("A" & Rows.Count).End(xlUp).Row
For Each cell In Range("A1:A" & lastRow)
With:
Dim ColLetr As String
For i = 1 To Columns.Count
If Cells(1, i) = "DATA/HORA" Then
ColLetr = Split(Cells(1, i).Address, "$")(1)
End If
Next
lastRow = Range(ColLetr & Rows.Count).End(xlUp).Row
For Each cell In Range(ColLetr & "1:" & ColLetr & lastRow)
EDIT#1:
To address the Comments:
Dim ColLetr As String
For i = 1 To Columns.Count
If Cells(1, i) = "DATA/HORA" Then
ColLetr = Split(Cells(1, i).Address, "$")(1)
Exit For
End If
Next
If ColLetr = "" Then
MsgBox "DATA/HORA not found"
Exit Sub
End If
lastRow = Range(ColLetr & Rows.Count).End(xlUp).Row
For Each cell In Range(ColLetr & "1:" & ColLetr & lastRow)