[Exim] bounce support

I'm trying to convert from qmail to exim and everything works fine but my bounce.

I had 2 mailaddresses on my virtual domain that I bounces all mail to.

Meaning that if you sent a mail to fx spam@??? the mail would be bounced to the sender with a notice saying that "spammer".

Now I'm trying to do that with exim but no luck yet. I've tried using the mail command but that doesn't really do that job. Fx it has a "sender" header that I dont like...

my qmail setting was:
|bouncesaying "spammer"

any help?????

using Exim 3.35