[exim] Performing some action is pipe results in an error?

If I'm using pipe in .forward and I'm piping to a perlscript and lets say
that perlscript has a syntax error that prevents it from running.

Is there anyway I can check the result of the pipe in order to do a "save"
of the message?

currently I'm savnig messages prior to the pipe in a backup folder but
that's way more than I'd like to save.