Crating .rdlc reports programmaticaly

Hey

Is it possible to create a full .rdlc report completely from code? By full I mean dataset assignment, grouping etc. If not, is it possible just to change the dataset (providing that the new dataset has the new schema as the previous one). I'm asking this because I need to use multiple databases in my application, and I don't know how to do the switch because of the reports (if I make them using the wizard, I have to use predefined datasets that are created by TableAdapters, and then I have the problem of changing connection strings)? Do you have some suggestions on how to do it?
Thanks