Before Insert SQL Trigger can't use INSERT or UPDATE statements?

All,

I was putting together a Before Insert SQL Trigger and was suprised to
learn that it can't use the INSERT or UPDATE statements...you get an
SQL0751 error:

-- Statements not allowed in an SQL BEFORE trigger are INSERT, UPDATE,
DELETE, ALTER TABLE, COMMENT ON, CREATE, DROP, GRANT, LABEL ON, RENAME,
REVOKE, REFRESH TABLE, and ALTER PROCEDURE.

What I was trying to do (error handling omitted, also note FILEB has
an identity column FILEB_ID)

create trigger FILEA_BEFORE_INSERT
before insert on FILEA
referencing NEW ROW as new_row
for each row mode DB2ROW

begin
if new_row.fileb_id = 0 then
insert into FILEB (fld1, fl2, fld3)
values (new_row.fld1, new_row.fld2, new_row.fld3);
new_row.fileb_id = indentity_val_local();
else
update FILEB
set (fld1, fld2, fld3) = (new_row.fld1, new_row.fld2, new_row.fld3)
where FILEB_ID = new_row.FILEB_ID;
end if;
end

I guess I'm going to have to use RPG for the trigger?

Charles