Decrease in amount and keeping the result remaining. How to?

[Klaus]

Hello,
I have a problem and I don't know what formula to use as an approach. How can I subtract the stock from the initial stock 24 each time it finds a value on the order so that on the following line I get the remaining stock: 12 .. 2 ..? As in the picture, what formula could I use?

[Arthur_Fong · Accepted solution]

There you go:

Refer logic at script level using peek() function.

Thanks and regards,

Arthur Fong

[Klaus · Accepted solution]

ok that would be a solution but let's say I don't want to use peek and
I have another variant as the formula in the expression on the stock column?