How do you re-map external buttons on the SPL?

[Guest slimgym]

I've hunted up and down the web but can't find out how to re-map in particular the IE button (to load Opera) and the media button (to load TCPMP). On the SP5m you just changed shortcuts Short_APx.lnk in \Windows but these files do not exist on the SPL and creating them does not have the desired effect.

I imagine it might be to do with the registry tweak to change the right soft key, but I've been unable to find key values for the SPL buttons.

I found vague and possible results for these registry keys HKEY_LOCAL_MACHINE\Software\Microsoft\Shell\Keys\ for hard keys and HKEY_CURRENT_USER\Software\Microsoft\Home\Keys for soft, but neither contain values which point to IE and without the key values I can't go any further.

The keycodes are listed here but of course the IE button does not get a mention :)