You can try something like this - it's not tested, and can be made more elegant, but this seemed the simplest to start with


Option Explicit
Sub test()
    Dim iFile As Long, j As Long
    Dim bStart As Boolean
    Dim textline As String
    Dim newline As Variant
    
    iFile = FreeFile
    bStart = False
    
    Do While Not EOF(iFile)
        j = j + 1
        Line Input #1, textline
        
        If textline = "Start line" Then
            bStart = True
            GoTo Nextline
        
        ElseIf textline = "This is the stop text" Then
            Exit Do
        
        ElseIf bStart Then
            newline = Split(textline, ",")
            Cells(j, 1) = newline(0)
            Cells(j, 2) = newline(1)
            Cells(j, 3) = newline(2)
            Cells(j, 4) = newline(3)
        End If
        
Nextline:
    Loop
    Close #iFile
End Sub