R help - Mar 2010 - Problem using ESS. Error message: "cannot change working directory"

Greetings R wizards.
I have the following problem using Emacs Speaks Statistics:

When trying to set a working directory, or when trying to read a file
that is in a directory that has the character "?" (note that it has a
"spanish accent symbol": ? )  R being ran from emacs tells me that the
directory doesn't exist, or that it can't be found, or:
> setwd("c:/Documents and Settings/Nicol?s")
Error in setwd("c:/Documents and Settings/Nicol??s") :
  cannot change working directory

I do NOT have the same problem if I try to do this directly with R
GUI. In my opinion, emacs is "telling" R "Nicol??s" when it
should
"tell" it "Nicol?s".

Any thoughts??

Thanks for your help. Thanks for R, and greetings to the hole
community of users, developers, etc.,

Nicol?s Leveroni