Sumproduct with Dynamic Column Headings

[lipper79]

Hello,

I've got a sumproduct formula based on multiple criteria, that is currently based on static columns (4Q16 data). I want the ability to have a toggle field (cell D31) that will allow me to switch the columns being used in the sumproduct based on the setting in the toggle field (eg. change to 3Q16 Data). I have attached my workbook to help find a solution. The highlighted portions of the formula (blue and green) are what I need to be tied to the column heading (cells E33 & E34) determined by the toggle cell (D31). I'm thinking INDEX MATCH, but I can't figure out how to incorporate that into my sumproduct formula.

Please let me know if you need me to clarify anything and I thank you in advance for your assistance.