In a test the following works for me with Word2000. You could use adir() to get the documents and loop through each:

oWord = newobject('word.application')
lcFile = GetFile("DOC")
oDocument = oWord.Documents.Open(lcFile)
lcPath = justpath(lcFile)
lcNew = juststem(justfname(lcFile))
oDocument.SaveAs(addbs(lcPath) + lcNew + ".htm", wdFormatHTML)
oWord.Quit()
release oWord
return