SQL & PL/SQL

Dear all
Below is my Function code, It is compiled successfully.
create or replace
FUNCTION ITEM_DESC (ITM_CODE IMS.ITEMS.ITEM_CODE%TYPE) RETURN
IMS.ITEMS%ROWTYPE IS
REC ITEMS%ROWTYPE;
BEGIN
SELECT ITEM_DESC INTO REC
FROM IMS.ITEMS
WHERE ITEM_CODE = ITM_CODE;
RETURN REC;
EXCEPTION WHEN NO_DATA_FOUND THEN
RETURN NULL;
END;

now I want to used it in SQL query, I want to select only one coloumsn (item_description)
how it could be please guide.

thanks