SQL Reporting Services Question

I started using reporting services to write some reports at work. I have a questions I can't seem to find an
answer to anywhere in the help content. What I need to do is hit a different database, based on a report parameter.
I'm guessing that I either need to change the database that the existing dataset points to at run-time based on the
report parameter. Or I could create completely a new dataset for each database I need and then just determine
which dataset to use based on the report parameter. I'm not sure how or even if either of these can be done in
Reporting Services. The first option is ideal, if it is feasible. The queries for each dataset would be the same as I need
the same data in each database. If anyone has any experience in this, please let me know, I could use some help! Thanks!

One way to work around this problem is to use of custom codes. Let say your functions from embed code will call functions from custom DLL passing RS parameters. In custom codes you will able depending on RS Parameters to use any ADO dataset.