UPC codes

We are getting UPC codes for our products. I'd like to add them to the store, but we're running a slightly older version that doesnt seem to support them. I did some digging on here and it looks like 2.4 supports UPC's?

If this is the case, at what level is the upc supported to? We need individual upc's to variant level, so that any variation has its own UPC (think of how SKU's are created, we need a upc for each unique sku...)

thanks

Product Variant has both
  Manufacturer part number
  GTIN (global trade item number)   [added in 2.40]

see demo