sounds to me like some kind of compressed installer. try running the installer under dosbox and it should extract and rename everything for you (you may have to install windows 3.1 on your dosbox first).
failing that, you can pick it up for cheap on steam, and even further beyond that, i think it's legal for you to download if you already own a physical copy. (don't quote me on this, i'm not a lawyer) don't be too surprised if the data has been tampered with, however. xcomutil is everywhere. also make sure that you apply the 1.4 patch if it doesn't already have it.
personally i recommend steam if you can't manage to get the data from your copy, as it is pre-patched to 1.4, and 0% modified.