Firewall: specify more than 1 src IP

I am trying to capture and redirect DNS queries to my pihole. I've got that working, but now I'm adding a second pihole to cover my child's devices, and I want queries from that device to be able to get out.

In /etc/config/firewall, I have this section:

config redirect
	option target 'DNAT'
	option name 'Redirect DNS queries to Pihole'
	option src 'lan'
	option src_ip '!'
	option src_dport '53'
	option dest 'lan'
	option dest_ip ''
	option dest_port '53'
	option enabled '0'

where I want queries to port 53 to be redirected to the pihole ( unless they actually came from the pihole itself. Is it possible to add a second IP to the option src_ip line, or use a netmask or similar?