correct XAVNB2001 setup??

Hi, I've been trying today to set up the two home-plug adapters XAV2001 and XAVN2001 and have successfully managed to use the WPS button on my Netgear router to set up the XAVN2001 which has now been moved upstairs next to my computer.

So far here's how my connection goes

downstairs - Netgear range max WNDR3300 router>XAV2001
upstairs - XAVN2001>MacBook pro (2009 model running Lion)
wireless - iPad2 & iPhone 4s

now all of the connected devices are able to connect, the MacBook can connect with WiFi turned on, wirelessly through the XAVN2001 or off via the Ethernet cable

Thus far, all good!! However, as it stands, the XAVN2001 is broadcasting a new network called "Netgear", with no security. Although this works and I am able to connect to the internet on my mobile devices, I had bought the Powerline adapters with the intention of extending my existing wireless network.

So after all that, my question is, does anyone know how I can set up the XAVN2001 to broadcast my current wifi signal, rather than a new one? I have heard this is possible. If this is completely impossible and ive misread the box and misunderstood various online reviews, how do I add a password to this new network? How do i make sure my MacBook Pro connects to the new network through Ethernet cable so that it, as well as my two mobile devices are on the same network so that i can perform various tasks such as using wake on Lan functions??

Any help greatly appreciated!

Simon