Get Value from Variable inside Variable.

public class Utils
{
  public static object MyEvaluate(string eval, object source)
  {
    return source.GetType().GetField(eval,
      BindingFlags.IgnoreCase | BindingFlags.NonPublic | 
      BindingFlags.Instance | BindingFlags.Public)
      .GetValue(source);
  }
}

Then you'll have to call it like this instead:

private int A;

// initialize it in the declarations or elsewhere
this.A = 10;
string B = "A";
var C = Utils.MyEvaluate(B, this);