freeze pane in VBA

In the attached spreadsheet I am having trouble trying to put a line in that will freeze row 4, so when the user navigates that row always will display. Thank you.

 Sub Classify()
Dim rngCell As Range
Dim wsLookUp As Worksheet


        '  Reformat annovar

    Range("AK1:BB1").Value = Array("Index", "Deleted", "Gene", "mRNA", "Deleted", "Deleted", "Coverage", _
                                   "Score", "A(#F,#R)", "C(#F,#R)", "G(#F,#R)", "T(#F,#R)", "Ins(#F,#R)", _
                                   "Del(#F,#R)", "SNP", "Mutation", "Frequency", "AminoAcid")

    Range("AL:AL, AO:AP").EntireColumn.Delete

    Range("AK:AY").Copy
    Range("A1").Insert

    Range("AP:BN").EntireColumn.Delete

    Range("AP1:AW1").Value = Array("Homopolymer", "Splice", "Pseudogene", "Classification", "HGMD", _
                                   "Disease", "References", "Sanger")


    Columns(3).Insert xlRight

    Range("C1").Value = "Inheritance"

    Range("1:3").Insert xlShiftDown

    With Range("A1:F1")
        .Value = Array("Case", "Last Name", "First Name", "Medical Record", "Gender", "Panel", "")
        .Resize(2).Interior.ColorIndex = 6
    End With
    
Range("A4:AX4").Select
Selection.Columns.AutoFit

    '  Step 2 Select Patient
 Application.ScreenUpdating = False
    With ActiveSheet
        lastrow = Cells(.Rows.Count, "CA").End(xlUp).Row
    With Selection.Validation
        End With
        With .Range("A2").Validation
            .Delete
            .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
                 xlBetween, Formula1:="=$CA$5:$CA$" & lastrow
            .IgnoreBlank = True
            .InCellDropdown = True
            .InputTitle = ""
            .ErrorTitle = ""
            .InputMessage = ""
            .ErrorMessage = ""
            .ShowInput = True
            .ShowError = True
        End With
    End With
    Application.ScreenUpdating = True

   
End Sub

thank you