Question about expressions with raise plpgsql statement in coming 8.1

Hi,

I would like to know if the PlPgSQL RAISE statement will be able to take
expressions for the format string in 8.1.
I checked the patches mailing list but I didn't find a clear answer.

I have to send error messages in several languages within PlPgSQL code.
I would like RAISE to work like that :

RAISE EXCEPTION get_my_format_string(MY_ERR_NBR,USER_LANG),a,b,a+b/c;

where the get_my_format_string returns a format string understandable for
RAISE for each valid combination of MY_ERR_NBR and USER_LANG.

Regards,