Editable spreadsheet

Hello, I am looking for a means of adding an editable spreadsheet to my website. We are a wholesale supplier and basically just want to duplicate our current .xlsx order form to our site so customers can simply fill in the order numbers and submit it to us.
In other words, on the order form list, I want a customer to fill in the number of each type of widget they want, see a subtotal on the row and then see the total at the bottom of that column.
All of the spreadsheet or table plugins I’ve looked at do not seem to be static, they do not allow visitors to edit particular cells and get a calculated subtotal or total.
In my ignorance, would have thought this was quite a simple thing to do but you know what they say about ignorance 🙂

Thanks

Chris

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