Moves the insertion point to an inter-character position
#include <GuiRichEdit.au3>
_GUICtrlRichEdit_GotoCharPos ( $hWnd, $iCharPos )
| $hWnd | Handle to the control | 
| $iCharPos | the inter character position Special value: -1 - end of text | 
| Success: | True. | 
| Failure: | False and sets the @error flag to non-zero. | 
| @error: | 101 - $hWnd is not a handle 102 - $iCharPos is neither a positive number nor zero nor -1 103 - $iCharPos exceeds the number of characters in the control | 
The first character of the text in a control is at character position 0.
Cancels text selection (if any).
Search EM_EXSETSEL in MSDN Library.
#include <GUIConstantsEx.au3>
#include <GuiRichEdit.au3>
#include <WindowsStylesConstants.au3>
Example()
Func Example()
    Local $hGui, $iMsg, $hRichEdit
    $hGui = GUICreate("Example (" & StringTrimRight(@ScriptName, StringLen(".exe")) & ")", 320, 350, -1, -1)
    $hRichEdit = _GUICtrlRichEdit_Create($hGui, "This is a test.", 10, 10, 300, 220, _
            BitOR($ES_MULTILINE, $WS_VSCROLL, $ES_AUTOVSCROLL))
    GUISetState(@SW_SHOW)
    _GUICtrlRichEdit_SetText($hRichEdit, "This is a test.")
    _GUICtrlRichEdit_GotoCharPos($hRichEdit, 8)
    While True
        $iMsg = GUIGetMsg()
        Select
            Case $iMsg = $GUI_EVENT_CLOSE
                _GUICtrlRichEdit_Destroy($hRichEdit) ; needed unless script crashes
                ; GUIDelete()   ; is OK too
                Exit
        EndSelect
    WEnd
EndFunc   ;==>Example