You need what is called a client-bridge. Many of the so called wan extenders can do this but they sell much simpler devices that are designed to connect to a tv or game console that only has a ethernet port. These used to be sold as gaming adapters but it is hard to get a good search term now days. Mostly the issue is going to be all the confusing options and ways to set these up if you buy the high end wireless repeaters. The simple devices require no changes or any special support on your router.
Now if you are the technical type you can take pretty much any router that supports dd-wrt and use that for this purpose.