[exim] dnsbl sender_host_address to file?

Hello all,

I'm trying to make a flat file, of IP's that I've already turned away
due to their existence on a DNSBL - easier.

I'm wondering if I can do this when I take the messages in rather then
through a cronjob that parses the logs.

Each day I seem to accumulate about 33 - 38k uniq hosts by
[grep,sed,awk]'ing the logs..

I'm looking for a simpler way..

Can exim do it?

Thanks in advance