I just want to add that at this time in 2020, if you want Apple's AAC Core Audio Codec running on fre:ac you have to download an old version of itunes. I tryed with the last one and the Core Audio Codec didn't show up in the codec configuration, so next I tryed to extract the "AppleApplicationSupport64.msi" from the executable, just as gypsythief said and no luck. That file is not in the last itunes executable package. The turnaround as I said is to download an old version of itunes and extract the file from there. I found a bunch of old versions in uptodown, but I don't know if I can put the url here. For me it is clear that Apple doesn't want anybody to use their codec in any way without using the full thing of itunes. If it is worth for something, I downloaded the v 12.7.1 of iTunes and the AppleApplicationSupport64.msi was there. Also if it matters I am using v 1.1.2 of fre:ac and windows 10 64 bits.
Next time, I may use the FDK AAC codec and the instructions that Robert Kausch has put in this post so gently and forget about Apple and their manners. Thanks for this really fine piece of software and the tips and advice for converting to AAC.