Hello all, Im customising some code I got online at the page http://www.contextures.com/xlForm02.html
I need some help editing the code in red. Basically, the code is used in conjunction with an excel form, so the user form is on one worksheet and the data collected is stored in another sheet. Currently there's a validation check to ensure that all cells have data entered. I want to adjust it since there are specific cells I wont need data in. So i figure the key piece of code is the line
 If Application.CountA(myRng) <> myRng.Cells.Count
so i want to adjust it to something like If Application.CountA(myRng) <> myRng.Cells.Count excluding cell D13. Im just not sure of the correct syntax. Hope i was clear enough. Thank you all in advance for your speedy responses.

Dim historyWks As Worksheet
    Dim inputWks As Worksheet

    Dim nextRow As Long
    Dim oCol As Long

    Dim myRng As Range
    Dim myCopy As String
    Dim myCell As Range
    
    'cells to copy from Input sheet - some contain formulas
    myCopy = "D5,D7,D9,D11,D13"

    Set inputWks = Worksheets("Input")
    Set historyWks = Worksheets("PartsData")

    With historyWks
        nextRow = .Cells(.Rows.Count, "A").End(xlUp).Offset(1, 0).Row
    End With

    With inputWks
        Set myRng = .Range(myCopy)

        If Application.CountA(myRng) <> myRng.Cells.Count Then
            MsgBox "Please fill in all the cells!"
            Exit Sub
        End If
    End With

    
        For Each myCell In myRng.Cells
            historyWks.Cells(nextRow, oCol).Value = myCell.Value
            oCol = oCol + 1
        Next myCell
    End With