adequickcopy,
Have you been able to determine how complex the HTML is? If it's not very complex (name, address, etc.) running it through a "pre-process" workflow to transform it to a usable CSV or text file may be doable. Also check out XHTML. Converting your HTML to XHTML would allow PlanetPress to "see" the files as XML and be used accordingly.

Hope this helps,
-nth-