Hi there,
I will be happy to help you with that. I have checked the doc and the example spreadsheet. The script will be bounded to the spreadsheet.
I can understand the purpose of the script, for each model you receive an order for, if the order exceeds certain limits, you need to split the order into multiple orders such that you deliver part of the order every 2 months. Such that for every model, the two month amount that will be delivered can't exceed 80.
The purchase order sheet won't be touched. The delivery planned will populated as you explained in details. How we will split the order will depend on column AC as you explained, other amount in columns A, I-AB, AD-AE will be splitted accordingly. The shipping dates will be also adjusted to allow for a two month period between successive shipments of each model.
I am an experienced Google Apps Script developer. I only work on that field. All of my reviews here are related to G Script projects and I offer after sale support =)
I will be happy to address any of your questions!
Sincerely,
Mohamed