Easy way to add google_product_category to features?

I'm using the data feeds add-ons for Google Base. I've added the required fields except for “google_product_category”. I see where to add it in the admin area on the product page, but when I add it to a product it doesn't export that field in the CSV. So I'm a little stumped on how to easily add the “google_product_category” to ALL my products using an excel template.

Is there something I'm missing?