RegEx to remove Square Brackets

Sorry if I have missed it but I cannot get any of the suggestions on this forum to work with the track below.

But what I am after is 2 regex's

Firstly i have this track

Niney The Observer - Blood And Fire [12 Version].mp3

I would line a regex to remove the Square brackets and everything within them

and the one that just removed the brackets.

Thanks in advance for any help

Action "Format value" ... or ... Convert "Tag-Tag" Tag-Field: _FILENAME Formatstring: $regexp(%_filename%,'\s*\[.+\]$',)

from:
Niney The Observer - Blood And Fire [12 Version]
to:
Niney The Observer - Blood And Fire

Action "Format value" ... or ... Convert "Tag-Tag" Tag-Field: _FILENAME Formatstring: $regexp(%_filename%,'\[(.+)\]','$1') From: Niney The Observer - Blood And Fire [12 Version].mp3 To: Niney The Observer - Blood And Fire 12 Version.mp3

DD.20150613.1121.CEST

To make sure to see only files having a filename with opening and closing square brackets, then for example set the Mp3tag Filter to ...
"%_FILENAME%" HAS "[" AND "%_FILENAME%" HAS "]"

... or ...

To make sure to see only files having a filename with a square bracket clamp at end of the filename, then for example set the Mp3tag Filter to ...
"$regexp(%_filename%,'^.+?[.+?]$',)" IS ""

DD.20150614.1840.CEST

Thanks DetlevD

Much appreciated