if location=a  then output

proc sort data=tmp(keep=location) out=tmp_1 nodupkey;by location;run;

options noxwait=no;
%macro pub_exp(in_value,out_path);
%if %sysfunc(fileexist(&out_path\outfile_&in_value..xls)) %then %do;
x "del /S/Q &out_path\outfile_&in_value..xls";
%end;
libname xls excel "&out_path\outfile_&in_value..xls";
        data        xls.out_&in_value.(dblabel=yes);
                set tmp;
          where location="&in_value.";
        run;
libname xls;
%mend pub_exp;

data        _null_;
        set tmp_1;
   call execute('%pub_exp('||location||','||'C:\mypath'||')');
run;