Navigating Textarea. How do you move to a line?

Use SendMessage EM_SETSEL. Example:

; .lib "user32.dll"
; SendMessage%(hwnd%, wMsg%, wParam%, lParam%):"SendMessageA" 

Const EM_SETSEL = 177
wndMain=CreateWindow("",200,200,200,200)
tarMain=CreateTextArea(0,0,100,100,wndMain)
lblMain=CreateLabel("Cursor pos: ",0,105,100,20,wndMain)
btnMain=CreateButton("Move Cursor",105,0,80,20,wndMain)
SetTextAreaText(tarMain, "Text Area Text Area Text")
Repeat
	Select WaitEvent()
		Case $803 : End
		Case $401
			Select EventSource()
				Case tarMain
					SetGadgetText(lblMain, "Cursor pos: " + TextAreaCursor(tarMain))
				Case btnMain
					SendMessage(QueryObject(tarMain,1), EM_SETSEL, 1, 1)
					ActivateGadget(tarMain)
					SetGadgetText(lblMain, "Cursor pos: " + TextAreaCursor(tarMain))
			End Select
	End Select
Forever