Unfortunately, applications like Lock-A-FoLdeR are specifically designed to stop people that don't have the right password from finding, viewing or modifying the contents of specific folders. As far as I know, the program doesn't have any backdoors, so if you lost your password, you pretty much lost access to that folder.
Reportedly, other users have been able to unlock a folder by moving it to a different computer, but I can't guarantee that this will work. In case you're trying this solution and the name is changed: instead of Folder Name, it is now Folder Name (32421231235), delete all the extra characters leaving just the folder's original name.