This surprised greatly me since it is a BIOS function built into the very lowest level of the machine, how could it not work? -
So I just tried it and it does work here - at least from the lock screen.
Hard to remember to do it right on a laptop with the weird numeric overlay (I kept pressing [Fn]xxx) but when I finally operated it correctly it worked. I have never bothered with the leading zeros [ALT]65 gets upper case "A".
Oh, and it is DECIMAL, not hex. R is [Alt]82.
The other approach would be to use one of the magic password deleting/changing/(possibly now recovering) boot CDs. I have done this a number of times and it works brilliantly. I have used cd080802 for years. I guess this won't work for the new "secure boot" versions of Windows.
Hmmm must take great care with passwords.
There are some listed here.
How to Figure Out Why Your PC is Beeping (Beep Codes)