Not real likely to work. The extender must be able to receive a strong signal and then send it back out. In general you would need to put it half way between your house and the neighbor. Putting in in your house the extender will get a crap signal level and then transmit out copy of the crappy data and in the process actually degrade the signal even more since it transmits on the same exact frequencies.
In most cases to get this to work you need directional bridge equipment. Many times you need the directional bridges on both sides.
You can look at equipment from ubiquiti to do this but at some point you have to ask is the complexity involved really worth it instead of just buying your own internet connection.