[Exim] Condition help

I'm trying to put two conditions together with an and,
without success. Both seem to work independently.
I think I've made a simple mistake but seem to be
going round in circles.

Any suggestions about what my mistake is would be
appreciated.

condition = "${if and {{ eq {$header_X-bham-spamfiltered:}{yes}{0}{1}} \
${lookup {$local_part}lsearch{/usr/exim/tables/master/optin}{true}{false}}}}"

Chris Bayliss