update only Variant Price and Cost per item via .csv

Hi,

I am hoping someone can help or point me in the right direction for help on my speciffic issue.

I have 85,000 (ish) products loaded into my Shopify store.

My supplier changes the prices on some of these every few months and I am looking for an effecient way to update the ‘Variant Price’ & ‘Cost per item’ collumns.

It is mostly all clothing items and only have max of 1 option (usually ‘size’), however many have multiple sizes per ‘Title’.

Can anyone advise what collumn headings that I need to upload so that it only changes the ‘Variant Price’ & ‘Cost per item’ but leaves all the other information as it currently exists.

I also have all these products under a seperate template from my other products in Shopify… Does anyone know if there is a way of changing the Product Template via the .csv?

I would be extremely greatful if anyone could assist me eith this. I am pulling, what hair I have left, out.

Thank you in advance, Craig