Custom Hashing Algorithms

So I have a bunch of hashes made with
md5(sha1(md5(sha1(sha1(hash('sha512',"password"))))))

Wouldn't it be awesome if you could create a custom file with 1 hash type and make it yourself using existing methods

0(100(100(100(100($hash)$salt)))) for example would be md5(sha1(sha1(sha1(sha1($hash)$salt))))

Something like this for example.