You could use some kind of tie magic to map key names. I didn't work it out, but you can use the code of Tie::Hash::Cannabinol (lol) as a starting point.

But honestly, i think you're better off if you rewrite your code, either by search and replacing field names or by changing to index driven processing.

update:
If you have control over the database, simple create a view/stored query or whatever you call it that maps your names and save it as _tablename. In your code you only have to change tablename to _tablename.

update:
Mentioning Tie::Hash::Cannabinol was not a joke (as the voting indicates). The module is really a good example for tie-ing hashes.