keyboard mappings

[toyfactory]

I'm using a Japanese 106-key keyboard and I want the characters on the
keys to match what comes up on the screen when I press them!  I've
selected the appropriate keyboard in the Keyboard Preferences.  If I
choose Japanese keyboard layout I just get the kana characters when I
type.  I can only get the correct keyboard layout and roman characters
if I issue the following command in a terminal: "setxkbmap - layout jp
-model jp106 -rules xfree86".  How can I configure this automatically? 
Should I use .bashrc, .gnomerc, the Gnome keyboard config file (wherever
that might be) or something completely different?  Oh for an
autoexec.bat!

Nick