fontconfig + mac + mplayer (how to add new fonts?)

[Selur]

I needed to add some additional fonts to the fontconfig mplayer uses so that it can display some .ass files properly.
After I while of testing I realized I had to create the folder /usr/share/fonts and copy my fonts into it.
This is fine for the moment, but I would prefer to keep my fonts in a folder per user, where the current user has write-access without having to enter a password.

From what I gathered it should be possible to create a local.conf which points fontconfig to an additional path.

Now I just don't know:

a. where this local.conf should be present
and
b. how it need to look like to point i.e. to ~/.fonts

-> Like always all help is appreciated.

Cu Selur