Use cell value in vba formula

I have 3 lines for each account and I have many stores (tabs) so I would like this in VBA if possible
the year columns ("E") lines are:
2015.00 is actual
2015 is a line to change/manipulate to see how line 2016 reacts
2016 contains formulas based on either the line above or the budget tables ,the reference budget tables that can also be changed.
Column ("W") is my helper column. I use this column to reference back to budget tables using index/match.
My question/problem is that I want the number from gallons sold to use in formula on PPG-Premium without manually looking up row/column, current formula =F164 * .1874. New formula to (=1589.98 * .1874)
Row 2016 will be same as above + PPGI. The worksheet has the formulas in cells.
I'm not sure, If Helper ("S") are same/equal use the gallons sold* PPG. Loop through each period.
I hope I explained this well.