If you use a TextBox control to display the text.
Using following code to scroll down:
Text1.SelStart = Len(Text1.Text)
PS:Assume that the TextBox control's name called Text1
And the TextBox's Proprety multiline must be true.
If you are using a control that contains a vertical scrollbar
Use this API function to scroll it
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Const EM_LINESCROLL = &HB6
Dim LineNumber As Integer
Call SendMessage(Control.hwnd, EM_LINESCROLL, 0, LineNumber)