Hi:
I agree, more information is needed. One point, however, SAS program files typically end in .SAS and these are NOT data files. They are programs. A .SAS program is just an ASCII text file and you should be able to open and read the program with any text editor, such as Notepad or Wordpad.
However, using a %include implies that you want to RUN/EXECUTE the SAS program. Definitely, need more information because asking how to "open" files that are clearly SAS programs doesn't make sense.
Cynthia