Overriding Core Options

Is there a way to override core options with per-game configs? PSX games tend to have a bunch of dead space at the top and bottom in Mednafen and I like to block that out with the initial/final scanline options. Unfortunately, different games have need different scanline settings. I have no problem overriding retroarch.cfg settings with per-game (autoload) configs but I can’t figure out how to override retroarch-core-options.cfg.

Uh, in the Configuration settings menu and then ‘Use per-game core options if available’ then when you have a game loaded go into the core options and at the top there is ‘Create game options file’.

That worked, thanks!