Case sensitive full text searching

Hi all:

Is there any way to create a case sensitive full text index? My target
is to make case sensitive full text searches but I don't know how.

I could create a configurario for full text searching:

CREATE TEXT SEARCH CONFIGURATION public.myconfiguration (PARSER =
pg_catalog.default);

CREATE TEXT SEARCH DICTIONARY public.my_dict (
TEMPLATE = pg_catalog.simple,
STOPWORDS = my_stops
);

ALTER TEXT SEARCH CONFIGURATION myconfiguration
ALTER MAPPING FOR asciiword, asciihword, hword_asciipart,
word, hword, hword_part
WITH my_dict;

And then create the full text index:

CREATE INDEX textindexsensible ON documento
USING gin(to_tsvector('myconfiguration',texto));

But default behaviour of Simple Dictionary returns the lower-cased form
of the word if it isn't in stopwords list. Is there any way to change
this behaviour?

Thanks in advance,

Mario Barcala

P.S. I am using PostgreSQL 8.3