The only Java Word APIs I'm aware of are POI and OpenOffice. DOC support in POI isn't maintained anymore, but maybe you're lucky and it does what you need. OpenOffice is more involved, but also better maintained. I have no idea if either supports forms. You can find some links on the AccessingFileFormats wiki page.
Andy hasn't posted here for more than a year, so I doubt that he'll be reading your question. But since I posted that, many improvements have in fact been made to Apache POI, so it might well be sufficient for your purposes.