[exim] System filter help

Hi guys,
I have been asked to setup a filter in exim that will redirect an email
to group1@??? to group2@???, where the subject line has
the phrase [auto] in it. Except when the subject line has RE: or FW: in it.

I setup the following:
# Exim filter
if
$h_to is "group1@???" and $h_subject contains "[auto]"
and $h_subject does not contain "RE:" and does not contain "FW:"
then
deliver group2@???
endif

The problem with this is that if anyone else is CC'd into the email then
they do not get the email as i get

original recipients ignored (system filter)

and if group1 is cc'd into the email then the filter does not apply.

Can someone help me?

TJ