Due to the limitations of the crypt format, and because it is a very common format on linux systems, wzdftpd also supports the MD5 format.
To use the MD5 format, the password is stored with the special prefix "$1$". The next characters (until "$") constitute the salt, and the remaining is the encrypted password itself.
The MD5 format is used in the "shadow" file, for exemple. So you can just copy and paste the encrypted password and it will work.