How do I set up an automatic column select

I need to set up a worksheet so that when I enter in R1CA, ABC; R1CB: 10.00;
R1CC 10.00, then if I later enter ABC in R20CA and 50.00 in R20CB
automatically the 50.00 will be entered in R20CC. (and so on with CDE and FGH
etc) Is this possible?