I will just leave this here so I can find it later...
* which data
files are available? 
* macro copied
from
http://documentation.sas.com/?docsetId=mcrolref&docsetTarget=n0js70lrkxo6uvn1fl4a5aafnlgt.htm&docsetVersion=9.4&locale=en;* with BQ mods to write file list to a sas table ;
%macro list_files(dir,ext);
%local filrf rc did memcnt name i;
%let rc=%sysfunc(filename(filrf,&dir));
%let did=%sysfunc(dopen(&filrf));
%if &did eq 0 %then %do;
%put Directory &dir cannot be open or does not exist;
%return;
%end;
   data work.&ext._files;
   attrib folder  length=$128;attrib filename length=$64;
   %do i = 1 %to %sysfunc(dnum(&did));   
   %let name=%qsysfunc(dread(&did,&i));
      %if %qupcase(%qscan(&name,-1,.)) = %upcase(&ext) %then %do;
        %put &dir\&name;
           folder = "&dir";
           filename = "&name";output;
      %end;
      %else %if %qscan(&name,2,.) = %then %do;        
        %list_files(&dir\&name,&ext)
      %end;
   %end;
   run;
   %let rc=%sysfunc(dclose(&did));
   %let rc=%sysfunc(filename(filrf));     
%mend list_files;
%list_files(&RAWDATA_FOLDER,
xlsx);
%list_files(&RAWDATA_FOLDER,
txt);%list_files(&RAWDATA_FOLDER, dat);
