Calculating when a given lot quantity is finished

I have made a work book for keeping track of frozen goods inventory on a first in first out basis.

main sheet has totals for all products then each sheet after that is dedicated to a certain product.

The problem im having is highlighting batches of a given product that arent yet finished, for example


Frozen Inventory.xlsx


lot 01-02 has 2 rows to accomodate being sent between two days, once the total quantity in equals the quantity out for batch 01-02 I want it to be disregarded (not highlighted)

lot 02-01 will need to be sent before lot 02-02 as it is older, I need a way to highlight all rows with lot 02-01 untill the quantity out is equal to quantity in.

So far I've used =COUNTIF($A$2:$A$100001,$A2)>1 to highlight batches with duplicate lot numbers, but this only give a false/positive value and doesn't actually take into account individual lot numbers.

If it makes it easier I could use a formula based on the date recieved.

Thanks!

Edit

Solved it myself, should have tried a bit harder before coming here. If anyone is interested formula is as follows

=if(([lot number in the row above]=[lot number in this row]),([cell above current cell]-[quantity out]),([quantity recieved]-[quantity out]))

Basically tells excel to subtract the amount sent from the total recieved if this is the first quantity sent from a given lot OR subtract the amount sent from the remaining quantity if this is not the first quantity sent from a given lot.