Hello again sabinefriesen,
I hope you've been well since we last heard from you. It sounds like you have a pretty specific need when it comes to the PST calculated for your COGs amounts, and I want to make sure you have the right direction on working with this information in QuickBooks Desktop.
When tracking, adjusting, and filing sales tax in QuickBooks Desktop, the sales tax module is designed to respond to many of the needs of business owners and bookkeepers. Our Set up sales tax in QuickBooks Desktop gets things started and has a variety of other articles that are great for working with this module.
For your situation, however, it may mean doing some manual work since you're looking for something so specific. While the Sales Tax menu includes the option to Adjust Sales Tax Due, it's sounding from this like you're looking for something a bit more specific than that. For that reason, I recommend connecting with an accountant.
An accountant, especially one that knows QuickBooks Desktop, is a great asset for situations like this as they can let you know how this sort of reporting should be reflected in your books. If you don't already have an accountant you're working with, our Find an Accountant page allows you to search your area for QuickBooks-certified accountants near you.
If you did have any further questions or concerns about how the features in QuickBooks Desktop work when it comes to sales tax, I recommend contacting our support team to have a one-on-one conversation to make sure everyone is on the same page and give us the opportunity to see what you're seeing. Our article Intuit QuickBooks Desktop software support policies highlights the ways to get in touch.
I wish you the best moving forward with this. :)
