using uCalcSoftware; var uc = new uCalc(); static void LogMessage(uCalc.Callback cb) { string msg = cb.ArgStr(1); // In a real app, this would write to a file or log service. Console.WriteLine("[LOG]: " + msg); } uc.DefineFunction("Log(message As String)", LogMessage); uc.Eval("Log('System initialized')"); uc.Eval("Log('User logged in')");