[Exim] Mail Forwarding w/o local part

Hello,

I'm trying to forward email to another host (which I
can't control). I've setup the aliasing director seen
below. The error message I'm getting says there's no
local_part for the address I'm trying to forward. I
don't want a local_part. I want to forward just a
couple addresses, none of which have an account of any
type on localhost. Does anyone know how I should
modify things to make this work?

forward_aliasing:
driver = aliasfile
file_transport = address_file
pipe_transport = address_pipe
file = /etc/exim.forward
search_type = lsearch

Thanks,
Nathan