Is is possible to allocate sales tax to a specific project when it's going to a liabilities account because it will be reimbursed to us (we are a non-profit)?

I am doing the bookkeeping for a Canadian non-profit, and one perk of non-profits is that they can claim half of the federal sales tax paid in expenses. Our GST goes into a GST payable liabilities account until the end of the year when we apply for the rebate. As a charity our funding is defined by a number of contribution agreements which I track with the QBO Projects feature. I've encountered a problem where the GST is not accounted for in the Project expenses - the bill will list the full amount but the Project will be short that 5%. For example, a bill for $100 will list as $105 in total, but on the Project expense report it will only list $100.00. It is irrelevant to our funders that we are claiming the GST back in our annual filing, as the full GST is an eligible expense in the contribution agreements. Is there a way to make sure that all the taxes paid are included in the Project expense tally?