This is not a working example -- I'm asking about the principle...
Here we have the often seen code to detect a double-click on an item in one ListBox (ID in $idListBox is of course created by other code).
To catch that ListBox item, I have only added $sBookmark to it. This could be a pick list application.
$idListBox = 0x004A0FB0
GUIRegisterMsg($WM_COMMAND, "_WM_COMMAND")
Func _WM_COMMAND($hWnd, $iMsg, $wParam, $lParam)
#forceref $hWnd, $iMsg
Local $hWndFrom, $iIDFrom, $iCode, $hWndListBox, _
$sBookmark
If Not IsHWnd($idListBox) Then $hWndListBox = GU