Private Declare Function SendMessage Lib "user32" _
  Alias "SendMessageA" (ByVal hwnd As Long, _
  ByVal wMsg As Long, ByVal wParam As Long, _
  ByVal lParam As Any) As Long
 
Private Const EM_GETLINECOUNT = &HBA

<font color=green>' Anzahl Zeilen ermitteln</font>
lngLineCount = SendMessage(RichTextBox.hwnd, _
  EM_GETLINECOUNT, 0, 0&)