What reader do you use? Should be an option to turn off automatic link detection.
Post a sample PDF and DWG.
You may need to use brackets, parenthesis, different font, etc. for the file names, I do believe that is the way it works with the "." in the word.
P.S. I just checked Adobe sight, supposedly certain fonts should make them work. Monospaced Fonts?
Which ones have you tried?