I don't know how it would fit but anything is possible with a little modification and body work. What you would probrably have to do is take some measurements of the civic spoiler and see where the measurements are in relation to the 6th gen spoiler, and figure out what modifications would be needed.
Definately would suggest you take some measurements before you go drilling any holes, or if you can at least test fit the spoiler to see how it would look then decide.