An optimisation I've thought of for this, even though the thread is long dead, is to lc the original string, and have all the strings to match as upper case, then all you need do is:
$string =~ s/$_/$_/i for @$qRef;
I'm sure the regex is considerably faster for having taken the executable bit out of it.
in reply to Re^2: Regexp string concat
in thread Regexp string concat