Code:
on ^*:HOTLINK:*//*:*:{ if ($regex($1,[a-z0-9]*\:\/\/..*)) { return } | else halt }
on *:HOTLINK:*//*:*:{ if ($regex($1,[a-z0-9]*\:\/\/..*)) { run $1- } }


But yes, having it check for protocols automatically would be nice.