[Exim] $pipe_addresses yielding $address_pipe

Hello all,

I've got a problem with the $pipe_addresses variable. I'm a client of
a virtual hosting provider, and I have all mail sent to my domain come to
my account. Then I pass it all to a script which decides what to do next.
Naturally, I have to know what was there in RCPT TO: commands (and there
may be more than one for the same domain). I've tried to use

#Exim filter
pipe "/home/my_domain/mail_entry $pipe_addresses"

which is supposed to give me all RCPT's as parameters. But what I
actually get is

arg[0]: "/home/my_domain/mail_entry"
arg[1]: "|/home/my_domain/mail_entry $pipe_addresses"

and I have no way at all to get at RCPT's, since $original_local_part@
$original_domain holds only the first of them (and $local_part@$domain is
"my_domain@???"). Could somebody tell me, am I doing
something wrong? I'm asking that here because my provider's technical
support seems to know as little. Exim version 3.36.

Thanks,

Helen