Anyone doing self-remiting taxes?

This is a fairly common situation in Canada. We’re in the province of Alberta. We purchase a ‘thing’ to use internally from the next province over, British Columbia. There are two tax jurisdictions in the BC area: GST and PST. The vendor charges me GST as it is a federal tax. However, they do not charge me PST since I am not physically located in that tax area (British Columbia). Here’s the catch. I still have to pay (self-remit) PST to the government of British Columbia. e.g. My vendor sends and invoice

Goods:  $100
GST:      $7
Total:  $107

I need to have PST calculated on the document and the value for that tax sent to a PST payable account - it should not be included in the payable to the vendor. Anyone doing/done this with Attain that can enlighten me on how to set this up? Regards, Django Dunn