Determining selection location in edit control

[egalvez]

Please tell me how to determine the selection in an edit control. For example, if my GUI has an edit control with several lines of text typed in it, and the user were to select one of the words, then click a button to bold the selection (to throw HTML tags before and after the selection) how would I programmatically determine what is selected? Do I need to determine both the line involved and the position of the selection on the line, or what, and how? Thank you.

[CyberSlug]

#include <GuiConstants.au3>

$GUI = GuiCreate("Example")
$editStyle = BitOr($ES_MULTILINE, $ES_NOHIDESEL)
$edit = GUICtrlCreateEdit("This is sample text already provided in the edit box.", 10, 10, 200, 00, $editStyle)
$button = GUICtrlCreateButton("Bold selection", 10, 150)

GUISetState()
While 1
    $msg = GuiGetMsg()
    If $msg = $GUI_EVENT_CLOSE Then ExitLoop
    If $msg = $button Then _SetSel()
WEnd
    
Func _SetSel()
    Local $text = ControlCommand($GUI, "", $edit, "GetSelected")
    ControlCommand($GUI, "", $edit, "EditPaste", '<b>' & $text & '</b>')
EndFunc

[egalvez]

Thank you.