Photo Albums with subfolders on iPad

Can someone help me on how to make subfolders albums on iPad? All photos stored on my computer are under a year folder (named 2009) and events subfolder. They are mixed under the 2009 folder.You can create albums or folders, but not a sub-album or sub-folder for the album or folder. When syncing photos, the iPad will ignore subfolders. All photos from subfolders combines into one big album.