Katchin
Drill through the wood floor and straight in to the concrete buy some long thru bolts hammer them in to the hole which is in the concrete the stud will be sticking up through the wood floor the lathe can be fixed in place. Just one thing once the thru bolts are fixed in place you will have studs coming up through the floor, should you want to put the lathe somewhere else at some point you will have to cut the studs off.
You can get the thru bolts here
http://www.thesitebox.com/screws-fixings/fixings/through-bolts/zinc-plated-through-bolts.aspxEd
