add drop down list to report which created by Report Builder

i am using ssrs report builder 2.0 to create reports.

and i know i can add parameter to the report and bind it to a dataset,then when running the report,there will display a drop down list of the parameter.

but i do not know how to do this: i have a table to display data in report body,and i want to display drop down list on the table header(normal just display static label),so user can filter table data by use this drop down list after running the report.

can you help me ?

thank you very much!