Daniel's recommendation of "pattern matching" is a certainly good choice if you strict file naming conventions are adhered to. I would recommend that you look into Microsoft VBA "Dictionary" objects or other "list" mechanisms where you could possibly look for an external "config" or standards file to conform with, and in the loop simply check the incoming file name against the "pattern" or "fixed file" list to accept or reject. This ensures that you do not have to stick with a hard-coded file name or naming convention and allow others to re-use your work.
HTH,
Bob
HTH,
Bob