entering combinations of numbers in 3 cells from specifed range

I working on some project, and i need a loot time to check all combinations of numbers. I am interesting is it possible to make vba macros, that will try combination of numbers in cells B1, B8 & B15 from range 15-50 so results in column R will be betwen -2,00%-3,00% if they is any, i mean that min and max value in this column be betwen -2.00% and 3,00% if it exist. On graph are values from r column, that helping me, for now, to solve this.

Sorry for bad englihs, thx