[exim] multiple virus scanners?

I'm currently using clamav as the "malware" scanner in exim4, and that
works fine, rejecting virusses at the DATA phase.

However, I'd like to be able to use more than one virus scanner. I
personally like clamav, however people at a site I administer want to
use a commercial scanner such as McAfee. Hence I want to configure
exiscan to use both, however I've not found any hints on how to do
this... When I used mailscanner it wasn't a problem, simply define
multiple virus scanners in de config.

Can anyone give any pointers how to do it?

Thanks,
Paul Slootman