Hi Ron, Thanks for suggestion. I tested your method, but didn't work on my case. Finally, I did them step by step, and get my result. data loop;    merge test1 (in=A) test2 (in=B);    by pgname;    index="&inexpmg";    if index="1" then do;         if A; end;    if index="2" then do;         if A & B; end;    if index="3" then do;         if A & ^B; end; run; proc sql noprint;     select pgname into :pgnameok separated by " "     from loop; quit; %macro loop; %let i=1; %let ds = %scan(&pgnameok.,&i.);      %do %while ( &ds ^= () );      %inc "C:\Program Files\......\..........\..................\...\\&ds..sas";        %let i=%eval(&i+1);      %let ds = %scan(&pgnameok.,&i.);      %end; %mend; Thanks for everyone's join for creating different ideas 😄 ... View more