Rolling Stock Count

Good morning,

Apologies if this is displayed somewhere else but I am confusing myself over it.

I have a spreadsheet with 1265 lines. The lines are either our current stock levels, new productions and the customer's orders. What I require is code for Excel to look at groups of items and then go through each date to make sure we have enough stock to cover future orders. I would like it to highlight where we won't have stock available (it becomes a negative value).

Any help will be greatly appreciate. Would you be able to write next to it what each part does, so I can learn for future?

Thank You

Thank you.

Sorry, I should've explained. The data stock quantity is in column C. If it is a minus it means this is the customer taking it out, and the positive numbers are our production coming in. The stock is the levels as of now. (Described in column A)

What I ideally need is for Excel to go through each product by date and make sure that we will always have enough stock to cover our customer's orders. If we don't, somehow make these stand out so my colleagues can do the necessary alterations.

=SUMIF($H$1:H5,H5,$B$1:B5)

This formula is what worked for me.