Hi Yorky and Welcome to PCHF
Does the wired router only have more than one ethernet port? IF so you can plug the laptop into another port and share the internet connection there.
Homeplug is a network system that operates via your mains lines, you plug a little adaptor into the wall and then I think that connects to a router which is also plugged into the wall somewhere else and is a different type of setup to a normal wired router.
This link explains more about Homeplug:
PC World - Just Plug It In: Networking Via Power Circuits