Advanced Search - Eyes on Final Fantasy Forums

Then click "search single content type," type in your name, and select show results as Posts

It'll only load the 200 first results, so you might have to load the oldest page to show more results. You can also select Go To Page and guess a page number, might be smart if you suspect there are very many pages, although if you guess too high you'll not get any results at all. There might be an easier way to do it, but I wouldn't know it.