Thanks microfab, this has worked on N810 and new Apple keyboard. Here's exactly what should be done: you turn the keyboard on, go on N810 to Control Panel>Bluetooth Keyboard, set to Generic PC and English, click Pair, then put your code (any 4 digits, may be 0000 for simplicity), then on Apple keyboard shift-enter 0000 or whatever you'd chosen. Then it works.
You may use dual language layout (so that you can temporarily type in the second language while holding down right alt) but it requires switching to Nokia SU8-W keyboard type and your language in settings (at least it works with Globster's russian layouts). Keyboard shortcuts will work also with Alt (for closing a window, press Alt-Ctrl-W).