Cryptacular already has this format which is not only usable but even similar to what you use to do:
````
$p5k2$2710$oX9ZZOcNgYoAsYL-8bqxKg==$AU2JLf2rNxWoZxWxRCluY0u6h6c=
````
Obviously you should not invent your own hash format when there is a usable original one.