ZoHo Creator Inventory Template Customization

I need someone to help with some customization of a Zoho Creator template. I’m using the inventory template from ZoHo and it works for the most part for what I need, but it needs some extra functionality for my products. I deal mostly with rolled goods. Rolls of vinyl, banners, etc etc. So I’m entering inventory in square feet. This is great, I always know how many square feet I have on hand, but it could be across multiple rolls. So what I’d like to achieve is Adding/Removing by roll numbers. I’ll provide an example below. I create a product(s) called Vinyl A and Vinyl B. I buy 2 rolls of Vinyl A, and 1 roll of Vinyl B. They are all 750 square feet per roll. So my inventory should show 1500 square feet of Vinyl A and 750 square feet of Vinyl B. This is easy, because the basic Zoho Template achieves this by default. But what I’d like to do, is when I remove something from inventory (sell something) I want to be able to specify the roll I’m removing inventory from. So in reality I have Vinyl Rolls A1, A2, B1. When I sell something I want to say I sold 200 square feet, but specifically from roll A2 for example. So at any time, I can see how many square feet I have on hand, and how many rolls. So in this case, I’d see Vinyl A now has 1300 square feet left in stock, but roll A1 is 750 square feet, and roll A2 is 550 square feet. I have some other little functionality I’d like, so this will be an ongoing project over a few weeks perhaps if everything works out on this initial project… so I’d like bids by the hour. Please let me know if you have any questions.