$myvar =~ /"           # First quote 
            (          # Capture text to $1 
             (?:       # Non-backreferencing parentheses 
               [^?"]   # Anything that's not a question mark or quote 
                |      # or 
               \?[^"]  # A question mark not followed by a quote (to allow embedded question marks) 
             )*        # Zero or more 
            )          # End capture 
          \?"/x;       # Followed by a question mark and quote 

##</code><code>##

$myvar = q{ abc"def??"ghi?"jkl };

##</code><code>##

$myvar = q{ abc"def??"ghi?"jkl };

print "matched <$1>" if
$myvar =~ /"           # First quote
            (          # Capture text to $1
             (?:       # Non-backreferencing parentheses
                (?!\?") # not question quote?
                .       # ok to inch along
             )*        # Zero or more
            )          # End capture
          \?"/sx;       # Followed by a question mark and quote



##</code><code>##

matched <def?>