Is there a QuickLook preview for plain-text files with unknown extensions?

A similar question was asked here but the answer refers to something called QL Stephen , which only claims to preview files with *no* extension. I need something that will show previews of files with extensions that are unknown to the Finder. They are all plain-text files. And, it needs to run on Lion (10.7). To clarify: I'm not looking for a default QL for *any* unknown extension, but rather for one that will preview certain *specific* extensions (e.g., **.sps**, **.fort**) as plain text.