List partitionning with subtr(column) : possible or not ?

Hello,is it possible with 11.2.0.3 Enterprise Edition to create a list partition with a substring of a column (or a function applied on the column) ?
I always have ORA-00907: missing right parenthesis

For example :
CREATE TABLE testp
(
  SESSIONCODE         VARCHAR2(25 CHAR),
  EVENTDATE           DATE
)
NOCOMPRESS
TABLESPACE WORK
RESULT_CACHE (MODE DEFAULT)
PARTITION BY LIST (substr(SESSIONCODE,1,3) )
SUBPARTITION BY RANGE (EVENTDATE)
SUBPARTITION TEMPLATE
  (SUBPARTITION SP_FR_0113 VALUES LESS THAN (TO_DATE('2013-01-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')),
   SUBPARTITION SP_FR_0213 VALUES LESS THAN (TO_DATE('2013-02-25 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN')),
   SUBPARTITION SP_FR_MAX  VALUES LESS THAN (MAXVALUE)