Key remapping ?

Hey guys,

I've read several boards on forum, and I understood that X substitutes its own
key mapping (with less flexibility than the linux base, but still sufficient).

Say, I want to remap aring to AltGr+o and Aring to AltGr+O.
At the moment, it's the O with a stripe through it, which I don't need.

I've read things about the loadkeys, dumpkeys and showkey commands, but it
doesn't seem to work.
In addition, I'd like this mapping to be valid in the command line as much as in
an usual X window. (Is that possible with this X substitution, or should we
remap in 2 places?)

Could somebody help me to understand what's going on, and possibly a procedure
to follow?

Thanks

@+ Daz