I'm not trying to be obstinate. If I ask a question the first time I'm going to ask it again when ignored because the answer would be genuinely useful.

Nearly all applications filter out that kind of induced key-event for security reasons. This is why faking a usable, 'real' key event is fairly difficult and means reconfiguring things in advance to allow for it (see matchbox-keyboard) -- it means feeding X11 an entire fake keyboard device to generate 'real' events. But depending on what the ultimate goal is you may not need to fake a key event, what is it? What does fn-scroll-lock even mean? most keyboards have no fn-key, and the fn-key is generally not mapped to a real key if it does, instead producing key combinations that could be completely different keys.