Help wanted, Mame layout file commandline switch?

[Felsir]

I would like to add a default view to the available layouts in the 'view' option. I have already made a couple of game specific layouts but I'd like to make one general lay xml file that Mame uses for all my games.
To clarify: i have a widescreen TV in a cocktail table, with the games rotated 90 degrees. When I want to play a two player game, the cocktail mode provides a nice full display for each player. However singleplayer games end up in the center, while I want those on the bottom half of the screen: close to the player.
So I made a 'gamename'.zip file with a default.lay in it. Works like a charm, but I rather not make a zip file for each game.

The mame documentation http://mamedev.org/devwiki/index.php?title=Layouts_and_Rendering_for_MAME_Artwork_System says that it is possible to point to a layout using the commandline, but doesn't mention what switch. I was unable to find it in the documentation either.

Anyone who can help out? What is the command switch the docs refer to, or is there any other method of achieving what I want?