Assigning values to array components.

Hello All,
I have a small application (based on sorting inet[] arrays) that
requires building an array of bigints, one for each inet in the array.
This is doable in most programming languages with a notation like:

inet_bigints[i] := inet2bigint(ip)

Unfortunately, plpgsql doesn't seem to allow that kind of assignment, as
loading the following into psql reveals:

create or replace function foobaz()
RETURNS bigint[]
AS '
DECLARE
answer bigint[];
BEGIN
answer[1] := 12345;
RETURN answer;
END;
'
LANGUAGE 'plpgsql';

When I try to run this:

select foobaz();
WARNING: plpgsql: ERROR during compile of foobaz near line 4
ERROR: parse error at or near "["

The system also won't let me initialize the array in the DECLARE
section. I've looked through the archives for the past few years for
hints about this, but haven't found anything. Is there a plpgsql
reference that's more 'complete' than the one that comes with the PG
distribution?

Any help greatly appreciated.
Rich Cullingford
rculling(at)sysd(dot)com