ARInvoice Misc Charge Tax Type

Hi Guys,
Does anyone know a way to link the InvcMisc to the InvcTax table?

I have an invoice with 1 misc charge and 2 detail charges.
So invctax has 3 rows, 1 for the misc charge and two for the detail line buts i cannot differentiate between them because invctax does not have the taxcategory.

I think i might have to join invcmisc to invctax on the reportable amount - which is a very average solution as there could be multiple lines with the same amount.