Redirect from example.com/sub to sub.example.com by htaccess

[forum11]

Can anyone tell me how to redirect from example.com/sub to sub.example.com by .htaccess by remaining query string as it is.

e.g: redirect
example.com/sub/details.php?id=01
to
sub.example.com/details.php?id=01

Thanks

[oddz]

^(.*?)/(.*?)/(.*?)$ $2.$1/$3