problem in using expression field

hi

i  created a dataset with name productinfo, and i used this expression as quary in this dataset;

but becuase i used this quary in expression , i cant used this field in my tablix in layout 

="SELECT    competitor_annual_Plan.year , competitor_annual_Plan.parent_competitor_nameName , " &
                      "sum(convert(float,competitor_product_info.quantitylastyear ))  as total"&
" FROM     competitor_annual_Plan , "&
                      "competitor_product_info "& 
                      "WHERE   competitor_annual_Plan.competitor_annual_Plan_code = competitor_product_info.parent_competitor_annual_codeName "&
" AND (competitor_annual_Plan.year = " & Parameters!year.Value & ") "&
 Iif(Parameters!product_family.Value="0",""," and competitor_product_info.MSC_product_family = " & Parameters!product_family.Value ) &
 " group by competitor_annual_Plan.year , competitor_annual_Plan.parent_competitor_nameName "