OK, so this is how I do things now:
-Using a automator rename routine, I replace the diffucult characters in the media (capture scratch) folder.
-I filter out all the problematic clips in the CatDV Catalog.
-For each clip I replace the same characters in the “Name” column, and do an “Attach Media” routine to the right media file.
Tedious, yes, but the director was “happy” to do it…