Hi Carlos,
We are sorry for any inconvenience caused to you.
Have a look at the following example which saves task baseline.
TaskBaseline baseline = new TaskBaseline();
baseline.Start = task.Start;
baseline.Finish = task.Finish;
baseline.Duration = task.Duration;
baseline.DurationFormat = task.DurationFormat = TimeUnitType.HourEstimated;
task.Baseline.Add(baseline);
I have attached a sample function which uses above segment. Please try the example and let us know your feedback.