I know this ain't much (nothing for autoit experts) but can help someone who was looking for a selectable label
(I used the hex values to avoid #include <EditConstants.au3>, the vars are in comment in front of the 2nd line)
$Form1 = GUICreate("Test", 351, 50)
$Label1 = GUICtrlCreateEdit("Selectable Label", 10, 4, 176, 20, 0x0800,0x00000020) ;$ES_READONLY, $WS_EX_TRANSPARENT
GUISetState(@SW_SHOW)
While 1
$nMsg = GUIGetMsg()
Switch $nMsg
Case -3
Exit
EndSwitch
WEnd
PS: I think the same could be accomplished with GUICtrlCreateInput()