SQL & PL/SQL

Hi,
I have the following tables:

persons p
-------
id
name
surname

emails e
------
emid
subject
sender
html_body
text_body

cods c
----
id --> fk on persons(id)
emid --> fk on emails(emid)
cod1
cod2
cod3

In the fields html_body and text_body I have some parameters that should be replaced dinamically.
These fields are:
NAME
SURNAME
COD1
COD2
COD3

I should replace those fields dinamically with the fields of tables persons and cods.

I have a procedure and inside I have a cursor like:
FOR cur IN (SELECT e.sender, e.subject,
REPLACE
(REPLACE
(REPLACE
(REPLACE(e.html_body,'_NAME_',p.name)
,'_SURNAME_',p.surname)
,'_COD1_',c.cod1)
,'_COD2_',c.cod2) AS html_text,
REPLACE
(REPLACE
(REPLACE
(REPLACE(e.text_body,'_NAME_',p.name)
,'_SURNAME_',p.surname)
,'_COD1_',c.cod1)
,'_COD2_',c.cod2) AS
text_text
FROM
person p,
emails e,
cods c
WHERE p.id=c.id
AND e.emid=c.emid)
LOOP
send email here
do some inesrts....

What I want to do is replace all those "REPLACE" statements with some function.
Does this have sense or doing it like this, even if it's confusing, is more correct and performaning?

Thanks in advance

Tarek