Monitor basename variables, Howto!

Hello people,
I have runing asterisk with a2billing 1.9.4.
I have set the record-call adhoc, so when user need to recod a call, it’s just doing on demand.

But when calls are being recoded, they are recorded with strange filename…

So, i’m turning into the documention to find out where can I set, for example the file basename to be ext-destination-date-houre… for example…
But i don’t know how can i set this variables, and where, in sip.conf, I guess, right, and which format i should give them??

I see that in asterisk agi script the basename it’s seted as:

So, should i do it here?? which is the variables then to make the recorded file as: ext-destinatio-date-hour ??

Thanks in advance,