Update Prices In Secondary Storefronts

I am making a mass update to my prices and i am using the new import tool. I can easily update the productprice for the store owner using that.

However, this doesnt affect the prices on the other storefronts (as it shouldn't, as I have different prices on different storefronts).

I have made an importfile with these 3 fields: "Product code Language Price" and made the secondary store the active storefront but nothing changes. I also tried adding a field Storefront and listed the secondary storefront in there, but still didn't work.

Is there any way i can import prices to secondary storefronts?