Bulk upload for one contribution with many attributions? Sample spreadsheet or recs?

The basic need is to use bulk upload to add dozens of attributions for one contribution. It seems like it’s probably possible but the article I found on attributions leaves quite a bit to speculation and I’m hoping to avoid a lengthy trial and error process and having someone manually enter 80+ attributions. If you’ve done this and have a sample spreadsheet or some guidance, I’d love to hear from you!

Background: We’re a small organization in Alaska, with one really new development person and maximum of one year of experience in EA for the most senior of us. Alaska is notorious for its Permanent Fund Dividend — Alaska residents receive dividend checks every October from a fund seeded by oil money — and several years ago the Pick.Click.Give. program was created, allowing folks to pledge and donate money from their dividend to Alaska nonprofits. Organizations receive the donations as one single check, along with a spreadsheet of the individual donors. 

Thanks for sharing your wisdom!