Creating a separate Ethernet network

I am creating a 'lab network' which is on a different range ( 10.10.3.X/24 ) , to do this I connected up Tomato ( Asus RT-N16 tomato 1.28 by shibby) to our main network , via the WAN , then I created a separate DHCP range then configured it to a VLAN and assigned to a single port on the router port ( LAN 2 )
This works perfectly for the Lab, however , is it possible to assign one or more of the other spare ports to the WAN ?

For example

Regular work network 10.0.0.x ( in Wan )
Lab...

Creating a separate Ethernet network