AnitaGaribaldi
Warlord
I suggest checking out the HoF FAQ, under the Autolog entry.
Edit: Let us know if that didn't answer your question.
I guess the answer is the "Silent/Default" settings.

From the FAQ:
Silent/Default- These options inform the mod how you wish it to start up. You can have this mod ask you at start up what to name your log file, always log to the same file, or log to a file based off of the player/leader name.
I think I want: "this mod ask you at start up what to name your log file". I have tried all combinations from silent/default settings without success.