Custom Logging

[Nasser Heidari]

Dear Folks,
I have added some additional radcheck options using checkval module.
For example I have several NAS Servers, and I've defined which user from
which NAS allowed to login.
Now I want to know is it possible to configure Freeradius in a way, that
when it rejects a user, it prints a custom error in log file?
e.g: user test is not allowed to login via NAS 1.2.3.4, it is configured
to login via 4.3.2.1 .

Thanks in Advance
Nasser