The keyboard shortcuts used in the Bengali menus should be keyboard combinations that can be created easily with a standard keyboard. So they probably shouldn’t actually be translated
e.g. officecfg/registry/data/org/openoffice/Office/UI/localize.sdf if we examine
“..GenericCommands.UserInterface.Popups..uno:WindowList”, which is the toplevel menubar entry “Window” in English, then the indic and CJK translations of pa-IN, hi-IN, gu-IN zh-CN and zh-TW all translate “Window” into their language, but
retain (~W) as the untranslated shortcut.
bn translations should follow the same pattern as the other Indic/CJK translations above.
A practical suggestion from the perspective of whatever little local language desktop usage I indulge in.