calculating the best combination

Hi, i have two varibles va, vb which are used in my formulas to calculate a result R across my data. I wish to find the best combination of VA and VB by
applying a 1% incremental increase to each varible to calculate diff results across the range of values eg lets say the VA and VB ranges are -1.03 - 3.44 for VA and -1.23-2.44 in VB what best combination of values produces the best Result.
hope you can help

I have attached the file (hiding some columns for ease of working. The two varibles are in column N & O at the bottom N229 and N230 VA values and O229 and O230 VB values. The formula which calculating the signals buy ,sell , no signal which produce the results is in column S. As previously mentioned i wish to change the varibles range for each VA VB to work out the best combination to use. n226, n227 expresses the full range for VA and o226 , o227 express the full range for VB and the values of n229,n230 and o229,o230 must fall within this range
So by working through 100% of the available range by 1% increments and 1% reductions in the ranges of both varibles i was hoping to see which combination works best ie which set of values for N229 , n230 and 0229, o230 from the range described in n226,n227 and o226,o227 produce the best result in z226
hope you can help
thankyou