Usage Contracts, Counters and Pricing Date

We have usage contracts set up with counters (net change, not absolute) and all is working as we would expect.

We've been asked to enter a price change for one particular usage mid-contract.

We see that we can do this by end-dating the current line in the locked price list and adding a second line at the new price.

Our problems come when we enter a counter reading with a date in the first pricing date range when the SYSDATE is in the second date range.

Because the counter reading is in the first date range, we want it to be priced at the original price, but it is picking up the price  based on OKS: Default Pricing Date, which we have set to SYSDATE. None of the alternatives, (Subline Start Date, Contract Start Date, Top Line Start Date and Contract Signed Date), will help us, as what we really want is the counter reading date.