Value in one Cell subtracted before another cell can start calculating

B17=160 and never goes above 160 B17 goes down when B18, A19, B20, B22 are subtracted. When B23 has a number value, that value cannot affect B17, and B18 cannot be subtracted from B17 until the value in B23 is = 0. Only then can B17s 160 value go down by subtracting B18, A19, B20, B22.

I have spent the better part of 2 months trying every combo I can think of and nothing seems to be giving me the desired results.

Any assistance is welcome.