data x;
input a$ b$ d$;
cards; 　 　
河北 2 9
上海 4 10
北京 - 11
;run;
data y;
input a$ m$ n$;
cards; 　 　
河北 1 3
北京 2 8
;run;
proc sql; create table f as
select * from y as left join x on y.a=x.a;quit;

data final;retain a n m b d;set f;run;

PROC EXPORT DATA= final
            OUTFILE= "D:\export.xls"
            DBMS=EXCEL REPLACE;
     SHEET="nameofsheet";
RUN;