[Exim] again lookup syntax problems

i've dome a script to import some infos from an external repository to 2 cdb files called

shortname.cdb (containing local_part)
mail.cdb (containing local_part@local_domain)

I would like to test incoming recipients during smtp dialogue but i have
some problems with syntax.

  accept  domains       = +local_domains
          endpass
          message       = unknown user
          condition     = ${if or {                                                                                     \
                                       {eq {${lookup{$local_part}lsearch{/etc/exim/shortname.domino}}}    {yes}}       \
                                       {eq {${lookup{$local_part@$domain}lsearch{/etc/exim/mail.domino}}} {yes}}       \
                               } {yes}{no} }
          verify        = recipient

Any idea? :-/

Thanks,

Riccardo