wasnt there some kind of forgotten password retrieving option, like enter mail and so on?
or you lost that mail account pswd too ?
anyway, maybe you can ask mods/admin to delete your account, and then register it again, then find some of your posts and ask admin to wire it to your account, so all other posts will be automaticaly yours
at least it worked after hack - all those new accounts were deleted and you just had to register again and find your post and admin did the rest, oh well, you know the story