Hi

Depending on the routers, some are able to act as wireless clients which is what you would want if you want to use it to connect your computer to your existing wireless router.

Another option would be to create a separate wireless "bridge" using two other routers, one by your computer and one downstairs. Some routers will allow this, if you could post the exact model numbers for your router I will be able to tell you.

I hope this helps.

Many Thanks

Leo