I’m not sure if asking here is appropriate, but I’ve spent about 40 hours of solid hunting trying to find the answer myself, and this is urgent. I’ve posted on a couple of subtitling-specific forums too - no response as yet.
In the UK broadcast format, the last two numbers refer to frames, but the other numbers refer to times. That means that neither the time or the frame options work, and although there is an option to change the number of digits at the end, it’s still time, not frames, so is completely wrong.
This doesn’t sound that complicated, but it turns out that it is. Or perhaps I’m just being stupid and missing something obvious - that is always a possibility.
I’m happy to use any other software as long as I can download it; I don’t have time to wait for a disc to be sent to me.