|Assuming you already have a WLAN (wireless LAN) setup wherever it is you're doing this (home, office) you would need to first ensure you're setting up the ASUS device to connect to your existing WLAN correctly.|
Once that's done, then any computer physically plugged into the ASUS device that is set to get it's TCP/IP settings from DHCP (on the router) should get proper TCP/IP settings and be able to access the internet.
In order to do this correctly you'll first need to know the IP address and subnet mask of the LAN side of the wireless router you have your WLAN configured on. You'll also want to know the DHCP Scope configured on the router too so you can avoid using an IP that's within the scope on your ASUS Device.
Even if the ASUS device has a DHCP server built into it, I would not use it if you already have DHCP enabled and configured on your router.
SOHO Router (LAN Side)
DHCP enabled = yes
DHCP Scope = 192.168.1.100 to 192.168.1.199
Default Gateway IP: 192.168.1.1 (IP of router)
DHCP enabled = no
As I said, you must first get the ASUS device working with your WLAN before you can ever hope to get a client connected to it working.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.