[exim] rewrite subject

Hi, i have this route rules for manage groups, and i would like rewrite the
subject of messages with the group name.
It's possible? How-to?
Thanks.

virtual_dom_groups:
driver = redirect
allow_fail
senders = ${if eq{Y}{${lookup
sqlite{/home/gestionaisp/web/sqlite/sqliteDb/mail.db select g.is_public \
from groups g, domains d \
where d.enabled = '1' and d.domain =
'${domain}' and \
d.domain_id = g.domain_id and
g.enabled = '1' and \
g.name = '${local_part}'}}} \
{$sender_address} \
{${lookup
sqlite{/home/gestionaisp/web/sqlite/sqliteDb/mail.db select c.member \
from group_contents c, groups g \
where g.enabled = '1' and \
g.id = c.group_id and \
g.is_public = 'N' and \
c.member = '${sender_address}'}}}}

data = ${lookup sqlite{/home/gestionaisp/web/sqlite/sqliteDb/mail.db \
select c.member \
from group_contents c, groups g, domains d \
where d.enabled = '1' and \
d.domain = '${domain}' and \
d.domain_id = g.domain_id and \
g.enabled = '1' and \
g.id = c.group_id and \
g.name = '${local_part}'} }

local_part_suffix = -*
local_part_suffix_optional
retry_use_local_part
reply_transport = address_reply
pipe_transport = address_pipe