[MacPerl] using references with hashes

Good morning/afternoon/night,

To avoid cluttering scripts with intricate expressions I tried references, 
with mixed results. e.g. instead of:

   delete $H{one}{two}{three}[0]{four} if exists $H{one}{two}{three}[0]{four};

I'd prefer to write:
   $ref = \$H{one}{two}{three}[0]{four};
   delete $$ref if exists $$ref; # or somesuch.

While I could get each, keys, and values, out of references, I haven't figured 
out a working syntax for exists, delete, and growing hashes.

Perhaps someone could suggest a right way. Thanks.