virus flexibility?

[Chris-Bellsouth]

I have sophos and clamav installed on my MS system which is performing
duties for several domains.

I have "Virus Scanning = rulesfile.conf"

In the rules file I have this file currently set to reflect:

To        example.com    yes
To        example.net      yes

then I have "Virus Scanners = sophossavi clamav"

What I'm wondering is, if I wanted example.com to use both scanners and
example.net to use only one could I use a rules file for "Virus Scanners"
like the following:

To     example.com     sophossavi clamav
To     example.net       clamav


???

Thanks in advance!

CT