Please try with that
rptMYReport objRpt = new rptMYReport ();
objRpt.SetDataSource(reportHeader);
objRpt.SetParameterValue("Parameter1", "value1");
objRpt.SetParameterValue("Parameter2", "value2");
Here,
rptMYReport is my Report
reportHeader is my DataTable.
Parameter1 && Parameter2 is your crystal report parameter that you define in your report viewr.
value1 && value2 is the value that you want to pass.