SQL & PL/SQL

Hi

I'm trying to find a solution for my problem but I can not find out any good idea..

Could you please help me?

I would like to mask a string like this:

- I want to mask only Words, which contain only A-Z and so, that the first 3 characters can be original and the remain should be replaced with *.

The Simpson family consists of fictional characters featured in the animated television series The Simpsons, which debuted on Fox in the U.S. on December 17, 1989..

The Sim**** fam*** con***** of fic****** cha******* fea***** in the ani***** tel******* ser*** The Sim*****, whi** deb**** on Fox in the U.S. on Dec***** 17, 1989..

Any idea?

Maybe in this direction but I can not go further:

SELECT x_text, REGEXP_REPLACE(x_text, '([^| ][A-Z]{3})([A-Z]+)', '*', 1, 0, 'i') AS X_TEXT_NEW
  FROM (SELECT 'The Simpson family consists of fictional characters featured in the animated television series The Simpsons, which debuted on Fox in the U.S. on December 17, 1989..' AS X_TEXT FROM DUAL);

Thanks in advance!