proc contents data=aaa out=alabel;
run;

data newlabel;
  set alabel;
        labelnew=cats('aa',label);
run;

变量很多，怎么写更好

proc contents data=aaa out=b;
run;

data step1;
        length code $200;
  set b;
        labelnew=cats('aa',label);
        code=cats(name,"=",quote(cats(labelnew)));
        keep code;  
run;

data step2;
    set step1 end=lastobs;
                if _n_=1 then call execute("data newaaa; set aaa; label");
                call execute(code);
run;
;run;

多次执行相同的操作，自然当用循环。