Hello Nicola
The stock quantity adjustment feature which is where users tracking stock adjust their stock creates transaction journal against the stock asset account and the stock shrinkage cost of sales account. An example of the journal adjusting stock quantity is shown below. It adjusts the amounts in that section. Unless you are wanting to use a different account to track this then we would advise to speak to an accountant
If stock tracking is turned off when you buy and sell the item the quantity will update and you can run a report on he product in product and services which will show this.
Can we just ask is there a reason that you do not want to track stock but adjust it?
Emma