You are supposed to shoot the window from *inside*. Stand by the grated window near the door which can't be opened. Indy will mention the broken window. Eventually, he will auto-aim the window with the revolver, then you should be able to shoot it.
Nevertheless, if you don't succeed I have a savegame at
ftp://ftp.soulianis.com/archive/indy...indow-shot.nds. Note that you need the
Update 1.2 to apply my savegame files.