WPA network: add WEP access securely

Hi, I currently have a wireless network set with WPA encryption, MAC address filtering and the SSID hidden. I have a couple of desktops (1 wired, 1 wireless) and a laptop (wireless) connecting. We have few Nintendo DS that we would like to connect to the network but they cannot use WPA, only WEP.

I would like to buy another (cheapish!) router that I could set to WEP encryption for the DS to use and maybe the occasional guests with laptops. I would like these connection to use the bandwith but not actually be able to connect to the existing desktops and laptop that I have connecting to the existing wireless router. It seems that there is a way to do this. I have been searching the internet but have only managed to get confused from conflicting information. Can this be done securely? If so how? Are there any special requirements for the new router or features that would make this more secure/easier to set up? Some of the stuff I have read mentioned DMZ or WISP but it is confusing me.

Also, is there any other way to do this?

Thanks!!!

Good day!

Yes of course you may setup another cheapish router for your nintendo to utilize securely.Setting DMZ or demilitairzed zone is different.DMZ refers to opening of all ports on the router that makes your pc vulnerable on the internet.It is simply turning off the firewall on the router.

To keep things simple.Kindly tell me the model and brand of the current router you're using.