Formula Help for Amortization Schedule

I have the following amortization schedule:

Amortization Schedule.jpg

Each month I record interest and principle payments based on the current month, in this example, I put in 8/1/17 in a cell. In another cell, I am trying to sum up the remaining interest but not all of the remaining interest, just the interest that follows 12 months from the date I put in which was 8/1/17.

Is there a way to do this? Let me know if I need to provide more information.

Thanks

No, not a training assignment but a task that no one in my team knows how to fix. I figured I could just do a vlookup on the date within the schedule but I don't know how to sum just the 12 months starting at the date that I enter.