How to give column name for grouped columns in matrix in report viewer in .net

 Hi
I am using a matrix in report viewer. in the matrix for the first two columns grouping is done, but i am not able to give the column heading for the first 2 columns.So i have added a table to that two columns and given column names.The problem is when i export the data to the excel the data(column names)which is in table is not exporting saying an  "Data Regions within table/matrix cells are ignored.". 
 
Regards.
 
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