child node loop

Private targetSheetName As String
Private Sub UserForm_Initialize()
    ' Import CSV data into a new sheet
    Dim newSheet As Worksheet
    Set newSheet = Workbooks("RaceCardAnalyser.xlsm").Worksheets.Add
    With newSheet.QueryTables.Add(Connection:= _
        "TEXT;C:\Users\Contango\Desktop\Racecard Analysis Project\Racecards\racecards.csv", Destination:=newSheet.Range("A1"))
        .TextFileCommaDelimiter = True 'Set delimiter to comma
        .TextFileParseType = xlDelimited
        .Refresh
    End With

    ' Store the name of the new sheet
    targetSheetName = newSheet.Name

    ' Populate TreeView with data from imported sheet
    Dim currNode As Node
    Dim prevRaceCourse As String
    Dim raceCourse As String
    Dim raceTime As String
    Dim currRow As Long

    ' Start on row 2 to skip header row
    currRow = 2

    ' Loop through all rows of data
    Do While Worksheets(targetSheetName).Cells(currRow, 3).Value <> ""
        ' Get current race course and race time
        raceCourse = Worksheets(targetSheetName).Cells(currRow, 3).Value

        ' Convert the fractional value to a time value
        raceTime = Format(Worksheets(targetSheetName).Cells(currRow, 2).Value, "hh:mm")


        ' Check if race course has changed from previous row
        If raceCourse <> prevRaceCourse Then
            ' Add new parent node for race course
            Set currNode = TreeView1.Nodes.Add(, , raceCourse, raceCourse)

            ' Set parent node's tag to race course
            currNode.Tag = raceCourse

            ' Store current race course as previous race course
            prevRaceCourse = raceCourse
        End If

        ' Add child node for race time
        Set currNode = TreeView1.Nodes.Add(raceCourse, tvwChild, , Format(raceTime, "hh:mm"))

        ' Set child node's tag to race time
        currNode.Tag = raceTime

        ' Move to next row
        currRow = currRow + 1
    Loop

    ' Sort child nodes of each parent node
    Dim parentNode As Node
    For Each parentNode In TreeView1.Nodes
        Dim childNodes As Nodes
        Set childNodes = parentNode.Child
        childNodes.Sort Key1:=tvwText, Order1:=tvwAscending
    Next parentNode




End Sub
Private Sub UserForm_Terminate()

    ' NOTES: Remove the sheet created when the form was initialized
    Application.DisplayAlerts = False 'Suppress alert message
    Workbooks("RaceCardAnalyser.xlsm").Sheets(targetSheetName).Delete
    Application.DisplayAlerts = True

End Sub