Problem with dynamically calculating numbers

I need to tap into the knowledge of the forum. I'm trying set up my model so that I can enter in a year and quarter number and my excel worksheet will automatically calculate the accrued revenue and enter it into the correct cell. Objectively, I would like to have the spreadsheet calculate a number representing the last 8 quarters of sales depending on the year/quarter entry.

I have attached an Excel file to better explain the scenario. If you look at line 5, I have this company will start paying money in Q3/FY18. So in the FY18 box, I want the entry to calculate a payment of past sales equaling a multiplier times the last eight quarters (including the first quarter) which is 25% of FY16, all of FY17, and 75% of FY18. This would the payment for past sales, and to this I would add 25% of the FY18 forecast to represent a payment for Q4/FY18. FY19 and onwards would just be the forecast number.

The challenging part is making the formula dynamic so that I can change either the year or quarter and the formula would recalculate the amount and put it in the appropriate cell.

Is this possible?


Cory