Evaluating IF statements at runtime

Question

Hi,

I have a need to evaluate IF THEN ELSE statements at run time. I am trying to find an example in the simplest form. I am basically creating a "Rules Manager". I need to take values from my program at runtime (read from a file) and manipulate them. For Example:

IF (customerName == "test")
    customerName == "smith";

However I need these "rules" to be stored in a separate file and not hard coded. The customerName would be coming out of my program however the IF conditional would need to be read from a text file and evaluated at runtime.

Can anyone point me in the right direction here? A basic example would be a great help.

Many thanks!