It's nearly always easier and quicker (in coding time if not execution time) to code that sort of test using separate regexes and boolean operators than it is a single regex.
$_ = "hello Gags";
if( /hello/ and not /Ga/ ) {
print 'Matched'
}
else {
print 'Failed'
};
Failed
Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algoritm, algorithm on the code side." - tachyon