Testing expansion in exim4

General expansion testing (needed this for testing Setting outgoing IP:

exim4 -be '${lookup{string_to_get_value_from}lsearch{file_to_look_in}}'

or

exim4 -be '${lookup{string_to_get_value_from}lsearch{file_to_look_in}{$value}{default_if_not_found}}'

etc etc.