Thanks for all the replies.
I did some tests with the "custom web links" feature, and here is what i discovered:
Using
file:///$RxReplace(<URL>,"^(.*?\\)Fichiers musicaux","$1Clips musicaux")
as a web-link works only on the preview in the template editor; but as soon as i test the link in the track info panel, it doesn't work.
I can notice on the error window that it had not achieved the regex and still display "Fichiers" in the url, instead of "Clips".
For it to do the expected folder's name replacement, i simplified the regex with a simple string, but i still use the $RxReplace function
file:///$RxReplace(<URL>,"Fichiers","Clips")
But it still doesn't fully work because every special characters are badly encoded in the end.
So i had my function which replace my folder's name and the file's extension:
file:///$RxReplace($RxReplace(<URL>,"Fichiers","Clips"),.flac,.mp4)
Then i thought having to make several nested replacements for every special characters, like this:
file:///$RxReplace($RxReplace($RxReplace($RxReplace($RxReplace($RxReplace($RxReplace($RxReplace($RxReplace(<URL>,"Fichiers","Clips"),.flac,.mp4),%3A,:),%2F,/),%20," "),%5C,\),%28,"("),%29,")"),%27,')
But apparently, doing the replacement only for the first encountered special character (a colon in my case), was enough for it to "decode" every following other special characters.
So with this code,
file:///$RxReplace($RxReplace($RxReplace(<URL>,"Fichiers","Clips"),.flac,.mp4),%3A,:)
it seems to work for any other following encountered common things, like spaces, brackets, comma, semicolon and parentheses
And as it was noticed on
this thread, it doesn't work with $Replace, even if you don't use a "real" regex.
I hope i was understandable enough, english is not my first language.
Thanks all for the help