search and replace possible on SQL?

hello,

again fiddling around with SQL...
wanted to loop over the Base search for Strings beginning with a
sequence and replace that sequence with another one.....

tryed the following:
update journal set description='Add '||(select id description from
journal subq where subq.description like '%PSF%').description where id=
subq.id;

but evidently it didn't parsed :D

so the questions are: 

can i make somehow a subquery and reuse the colums ? the system tryed
above doesnt seem satisfying .....

is there a way to achieve above functionality, or do i have to write a
frontend to make this?

in fact what i want to do using perl syntax:
$temp="Add ".$1 if /(PSF.*)$/;


-- 
ciao bboett
==============================================================
bboett@earthling.net
http://inforezo.u-strasbg.fr/~bboett http://erm1.u-strasbg.fr/~bboett
===============================================================
the total amount of intelligence on earth is constant.
human population is growing....