I guess what you're asking is, can you use this range extender as a simple network, w/ wired and wireless users.
To be honest, without the product in-hand, I can't be 100% sure. But since this is an extender and not a repeater, it means it should have TWO radios, one for the wireless client connection, the other for the wireless AP. And they should be independently configurable. So as long as it doesn't REQUIRE the wireless client connection to be established in order to setup the wireless AP (like a repeater would), it should work. The wired and wireless clients will simply be bridged.
Of course, you won't have a DHCP server in this configuration, so you'll either have to depend on DHCP auto-configuration on the clients, or use static IPs.
Aah thanks mate