[exim] Expansion of transport filters

Hi

For me it would be better to have a transport_filter_condition, but it does
not exist.
Is there a way to simulate one?

I tried:
transport_filter = "${if .... {/path/filter param param}{} }"

But that didn't work.
I would like to be able to set the filter name including it's parameters in
a file suchas:

transport_filter =
"${lookup{$local_part@$domain}lsearch*@{filename}{$value}fail}"

But I think, if "if" does not work, neighter will "lookup".

Any hints / comments ?


Regards,
Steffen