Relationship between payroll tables and service billing tables

My company runs business across various Canadian provinces, and since last year, BC has implemented a new Employer Health Tax that is not calculated during payroll.

Because we do service billing and invoice clients with employee wages and burdens, we have to create a custom report that calculates this tax and also displays the related service billing accounts.

The report that I am interested in creating will look something like the screenshot and accounting will do a manual entry to the operating account for the tax amount.

I have been trying to find how payroll tables F0618 and F0719 are linked to service billing information in table F0911 and F4801 so that I can find the operating account where to charge the calculated taxes, but I am not able to find the relationship. Does anyone have a suggestion about how to handle this?