POSIX (MySQL RLIKE) Regex to match A|B|C but eliminate D|E|F – PHP Versions

I had a completely working version on my Windows XAMPP testbed (in PHP)

SELECT... ...WHERE itemTitle RLIKE '(?=.*A)+(?=.*B)+(?=.*C)+^((?!D|E|F).)*$'

that stopped working when I moved the site to a real server with the error "repetition operator operand invalid".

Research says that the UNIX based server only supports a more basic RegEx that does NOT allow look-aheads or behinds..?

Six hours+ of searching and testing on my local site and the real server lead to no solution on my own.

To clarify, I need the (MySQL) to return records that have multiple matching strings (in a given column) but ELIMINATE the ones with a seconds set of matching strings… WITHOUT using any repetition operators!