Ssrs 2008 use more than 1 dataset

I am working on a new ssrs 2008 report since my company is using sql server 2008.

I am wondering if a specific rdl that contains 1 main tablix with several embedded tablixes can use more than 1 dataset for a specific report (tablix) that is being generated? If so, can you show me how a specific rdl can use more than 1 dataset?

I am asking this question since main tablix will use several embedded tablix. The new embedded tablix that I want to use has 6 control groups that can not be embedded in the 'main tablix'. Thus I am trying to find alternative solutions.

If you have any alternative solutions would you tell me what they are and how I can accomplish that goal? I am hoping not to use subreports.

can use more than 1 dataset at a time.