access to partial registers?

[Tupshin Harper]

Sorry for all the questions...these are the trials and tribulations of 
dealing with a newbie trying to get up to speed with the current state 
of parrot. So here's another question:

Is it possible and/or meaningful to read and write from a part of a 
register(e.g. a single word) in pasm?

As with my previous questions, I'm not really interested in pbc 
issues/format(with exceptions of course), just learning the intricacies 
of pasm.

-Tupshin