Could you define what "Microsoft Word's special characters" exactly are, e.g. list them.

You can filter character list with [ ] so if A T Y I would be special characters (which of course there aren't, just as an example), then you could remove them from a string with the following simple regex:

$string =~ s/[ATYI]//g;
[download]

If you have the special characters as octal code you could write this like this:

$string =~ s/[\123\124\145]//g;
[download]

(The numbers here are just random example numbers).

Please tell me if I missed something or misunderstood you.