Extract file from zip archive without writing to disk

I'm trying to extract a file from a remote archive (in this case a KMZ) that contains multiple files. I want to extract just one of them files without having to write anything to disk. I did find a thread that gets about halfway there (http://answers.unity3d.com/questions/27339/download-zip-file-with-wwwform-unzip-with-sharpzip.html). However, that one is Mac-only and writes to disk.

I have already written code (in c#) to download the zip file and verified that I can actually get a byte stream out of it that I can write to disk. Any thoughts about how to wrap this into an unzipper utility and get a single (text) file out of the mess?

Thanks much!