Try this:
;coded by UEZ 2011
#include <GUIConstantsEx.au3>
#include <GDIPlus.au3>
_GDIPlus_Startup()
Global Const $STM_SETIMAGE = 0x0172
Global Const $hBmp = _GDIPlus_BitmapCreateFromMemory(InetRead("http://aut1.autoit-cdn.com/forum/public/style_images/master/logo_autoit.png"), True) ;to load an image from the net
Global Const $hBitmap = _GDIPlus_BitmapCreateFromHBITMAP($hBmp)
Global Const $iWidth = _GDIPlus_ImageGetWidth($hBitmap)
Global Const $iHeight = _GDIPlus_ImageGetHeight($hBitmap)
Global Const $hGUI = GUICreate("Display PNG Image in picture control", $iWidth, $iHeight)
Global Const $idPic = GUICtrlCreatePic("", 0, 0, $iWidth, $iHeight)
_WinAPI_DeleteObject(GUICtrlSendMsg($idPic, $STM_SETIMAGE, $IMAGE_BITMAP, $hBmp))
GUISetState()
While True
Switch GUIGetMsg()
Case $idPic
MsgBox(0, "Information", "PNG image was clicked")
Case $GUI_EVENT_CLOSE
_WinAPI_DeleteObject($hBmp)
_GDIPlus_BitmapDispose($hBitmap)
_GDIPlus_Shutdown()
GUIDelete($hGUI)
Exit
EndSwitch
WEnd
Br,
UEZ