Mykola, this could probably be modeled by just using a tee and defining it as a "other". Make the leg and branch of the tee match that of the elbow, and the the other leg would be your reduced elbowlet. Make sure the SIF matches what is required for this kind of connection. You would want to use a very, very small reducer on the leg to get down to your connection, and remember that the outlet will need to be angled as well to align the the centerline of the elbowlet.
I would not suggest the beam method, that may give you incorrect results for the reactions you are looking for. Have you tried searching the help files? Sometimes they have these solutions in there, and I am sure Mike will help out as well if you don't find anything.