extended passkey in hcid.conf

Hallo,

my simple question to the bluetooth-code was to find out, how to make use of an "extended" passkey.
(But I didn't succeed: I'am not a real good C-programmer...)

IMHO a passkey is defined by the spec to be 16 byte (16*[0..255]).

In /etc/bletooth/hcid.conf you can enter something like >passkey "0123456789ABCDEF"<

But is it possible to enter non-numeric values here too? Perhaps as in:

echo -n -e "\xFF\xAA\x00" | od -t x1

TIA

Bernhard

PS:
CC me if you answer please. I'am not subscribed here and have limited internet access only.