Assign name to column excel in VB

Hello Developers, I have a problem that I am creating an excel book with its respective sheet name etc

I want to change the value to the column to put names I have tried with many methods but I do not know how

Dim xlWorkSheet As Excel.Worksheet
    Dim misValue As Object = System.Reflection.Missing.Value
    Dim j As Integer
    xlApp = New Excel.ApplicationClass
    xlWorkBook = xlApp.Workbooks.Add(misValue)
    xlWorkSheet = xlWorkBook.Sheets("sheet1")
    xlApp.Columns.Name("A") = "Fecha"
    xlApp.Columns.Name("B") = "Barra"
    xlApp.Columns.Name("C") = "CMG"

If you see I have tried with columns.name and I can not the error is the following

Exception from HRESULT: 0x800A03EC