How to reserve a nickname?

[spam.spam.spam.spam at free.fr]

Hello,

I am using ircd-hybrid-7.2.3.
I would like to reserve a nickname.
I already read doc/resv.txt but this is not what I want.

I would like to reserve a nickname with a password.

With some IRC, we can subscribe for an account with nickname and password on a
web page. After this :
- When a user use this nickname with no password, he can
- If, at the same time, an other user wants to use this nickname with the
password, the previous user will be renamed

How to configure correctly my ircd.conf in order to do this?

Thank you.