Final Update: this is what I used in the end...
Parses a string in a file. The string uses an apostrophe as line terminator. Ignores apostrophes predeeded by the escape character, "?". Clever enough not to parse the same file more than once.
perl -p -i.bak -e "s/([^?])'([^\n])/$1'\n$2/g" input.txt
perl: Invokes the command interpreter.
-p: p switch is 'assume loop like -n but print line also'.
-i.bak: i switch is edit in place, .bak is the extension of the backup file.
-e: e switch is 'one line of program'.
"...": Use double quotes for Windows OS.
s/.../.../g: Substitute. Match 1st and substitute 2nd. g means global.
(...)...(...): Groups - whatever the value between brackets winds up in $1, $2 etc.
([^?])'([^\n]): Match any apostrophes neither preceeded by the escape character "?" nor followed by a new line "\n" - three characters total.
$1'\n$2: Replace matches with the value of group one (see above) followed by an apostrophe and a new line(\n) and the value of group two - four characters total.
input.txt: File to parse.