function for random cell selection in a chart

Hi -- if this is possible within excel 2003 which function should I use?
To have several cells "interdependent" so that a value inserted in any one cell gives the corresponding values in all others -- as in a conversion chart.
If not possible in excel, what programme would do this?

Welcome to the Forum!

If you have two formulas that refer to each other, then that creates a circular references, which Excel tolerates but generally believes to be an error. If you then type a value into one of them, the other one will show a good value but typing in a value wipes out the formula. So you can't do what you want to do just using formulas.

The solution requires coding in VBA, Excel's macro language. It's kind of a big topic to provide a tutorial here. If you could show exactly what you want to do then perhaps I (or someone else) could write the VBA for you. I did one like this in another thread that you may find instructive.

http://www.excelforum.com/excel-gene...roll-bars.html

Here, there is a right triangle with one fixed side and the user can either input the length of another side or the angle. The code detects which one changed, and the calculates the other one.