options validvarname=any;
libname CDPrice "E:\datasets\Finacial\成都市每年各月城镇居民食品零售价格(周报).xls" mixed=yes;
run;

%macro aa;
/*%let s1=%str(CDPrice);
%let s2=%str(%"2009-04-02$%"n);/*此处的双引号在下面无法识别，被转化成单引号了*/
%let s=&s1&s2;*/
*%let s=CDPrice.'2009-04-02$'n;

%if %sysfunc(exist(&s)) %then %DO;
     %PUT &s;
     DATA T;
     set &&s;/**导致读入XLS错误/
     RUN;
     %end;
%mend aa;
%aa;