WPS isn't one of those listed, I don't know if you can open it with whatever you have and save as one of the listed ones or not. If not you have to get that PostScript driver and convert to PostScript and then ul that.
Either install CutePDF as a virtual printer and "print" the document to a pdf. Or you can save the document as a .doc (yes, Works have that ability, it just tries to scare you about loss of formatting) and then convert that doc using another utility (like this, but it might create a watermark)...
Or you could install OpenOffice instead of that horrible Works thingy, just remember to convert your wps to doc first. Then you'll have a free office suite, with more or less the same abilities as MS office, and you get the pdf export incorporated...