I am (intermittently) working on creating my own feed from my legacy invoicing software database to update the inventory in my zc database. This uses Pentaho Data Integration (free) to pull out stock data directly from the legacy db, manipulate it and stick it straight into the Zen Cart db. Automatically.

You could do the same to your feed. You can make almost any type of manipulation to the incoming data, building up a transformation by adding simple step-by-step blocks until it meets your requirements.
It is, quite frankly, awesome, for anyone looking to manipulate data.