different milters for different SMTP clients

[Ivars Strazdiņš]

Hi,
I have three separate milters - dkim signing, antivirus and spam check.
I’d like dkim and antivirus milter to be applied to all clients, but spam check 
only to non-local clients.
Is it possible to devise a map for that? The example for smtpd_milter_maps 
setting seems to be all or none approach - it seems not possible to configure 
postfix to apply only some milters based on client’s IP address.
Or any other approach to achieve this?
Thank you in advance,
Ivars Strazdins