How can I get the fireplace smoke smell out of my house?
If you can find the source of the smoke smell, you could try a chemical smoke remover like ZEP Smoke Odor Eliminator:  http://amzn.to/1DuEMww

If that doesn't work or you can't find the surface that is holding the smell (and hence cannot use a cleaner like that), then you'd likely need to treat the entire room with an ozone machine.  These are used by professional cleaners that rehabilitate structures that have suffered a fire.  They aren't cheap to buy, and I don't know if you can rent one.  See an example Ozone generator here:  http://bit.ly/1xAXiTM