If function with conditional formatting?

So, my issue is I have two columns with values, lets call them A1:A10 and B1:B10 and depending on what my value is in C1:C10, (Cx), I reference a value from either column A or B. I have done that using nested IF function and works just fine. What I am trying to achieve now is once I satisfy the condition for C>x, I want to always reference Column B instead of going back to Column A once C

Thanks