[Exim] How to disable rejects logging for particular errors

Hi!

I get about 150K of these spam generated log enties in my reject log file:

2003-12-23 23:38:25 H=smail.education.ru (primary.education.ru) [195.2.82.134]
F=<cbc@???> rejected RCPT <999support@???>: Unrouteable address

Of couse I can't observe the real problems in this mess. Can I by some non-source-code-hacking
means make Exim not log this particular error in _reject_ log for all my _local_ domains? It's
the problem of the sender, not mine.

Regards, Andrey Novikov