Loki said "however you could load the files locally and combine them together, then point it to the resulting file."
I have been doing that, mostly because manually loading 26 separate blocklists every time I update the IP Filter is more hassle than I am willing to tolerate; and, I was not sure about the answer to my question stated at the beginning of this thread.
Personally if I'm going to use blocklists, I prefer to use a separate application than my BitTorrent client, which also enables me to use these lists outside of the client
For windows there is PeerGuardian or PeerBlock (I switched to using Linux 8 Years ago, so don't know if these are still updated), or for Linux you can use Firestarter to whitelist/Blacklist or ipblock.