xkb: Setting a custom layout without root access

[Quiark]

Hello,

I have created a custom keyboard layout (basically dvorak with czech
symbols and special symbols accessible using right alt). It works fine
when I copy the file into etc/X11/xkb/symbols/ and use setxkbmap. You
can check out the layout here:
http://www.fi.muni.cz/~xplasil/tmp/roman_dvorak.xkb

The problem is that I would like to use this layout on the computers at
school and I don't have root privileges there. Therefore, I can't put
that file into the appropriate directory and setxkbmap doesn't work any
longer. I found an advice to use xkbcomp roman_dvorak.xkb :0.0 but that
does not work.

I guess I need to tell setxkbmap to load that file from my home
directory instead of the system xkb configuration directory, but I
couldn't find a way to do this.

So does anybody have any idea how to activate the layout as a regular
user, without root?

Thanks
Roman Plášil