However in post 17 of our forum sticky I describe how to add a router as a WAP. You can place that WAP closer to the area you need coverage.
There are WDS setups (see google) but that requires routers that employ WDS.
Yes you can try a RANGE EXTENDER (see google) but these are iffy as well. I like the solid solutions (see post 17 in our forum sticky.)
My sister in law has a wireless network in her house that works pretty well using their 2WIRE dsl modem. However, she also has a detached in-law unit where they are trying to get a connection, but so far the connection makes it to the outside of the door and once you get inside it dies. I was wondering what the easiest way would be to expand or extend their wireless connection to that part of their property without trying to run wires and set up a new router.