Find all text in brackets and replace with all capitalization

In the world we live in I find it difficult to believe I have been unable to locate the correct remedy I need for my issue with nothing more than my due diligence using Google search… but thus is the case. I am simply attempting to take a plain text document, find all words contained in brackets [word] and capitalize all the letters [WORD] using a regex. Unfortunately I have come up short… Any assistance would be greatly appreciated.

Just divide the actions in two steps: the first step is to find all the \[word\], then close the search window and execute the second step in UPPERCASE (apply it to the selection)

RegEx (Find All):

 \[.*?\]

then apply UPPERCASE (JohnSUN) - punctuation is not affected.