Uploading The Quantity Field For Products With Options

i see how I can create products with options, as well as specify "track inventory with options". I also see how I can specify manually what the inventory for each of these options should be. However, I can't find any documentation on how I can update the inventory on hand with a .txt file. Can this be done?

Seems like a pretty obvious "must have" feature of CS cart, but I can't find any info. What am I missing?

Please check the Product combinations tab on the Administration -> Import data -> Products page