Just read them with a data step. You can use the FILEVAR option on the INFILE statement to make the name of the file to read dynamic.
data want ;
set have ;
length actual_code $4000 ;
infile code filevar=code end=eof;
do while (not eof);
input;
actual_code=catx(' ',actual_code,_infile_);
end;
run;
If the files are too long to stuff into a single variable then output multiple observations per file.
length actual_code $200 ;
infile code filevar=code end=eof truncover;
do row=1 by 1 while (not eof);
input actual_code $char200.;
output;
end;