Timthumb : Allow hotlinking for some domains

Hi,
I am using WPML and i have a domain per language configuration. When I try to display thumbnails on my translations domains Timthumb sees it as hotlinking and refuses to do its job (for Justified Image Grid plugin).

So do you know how to force Timthumb to make an exception for some given domains ?

One solution would be to disable hotlinking protection in Timthumb and build an htaccess to make a custom protection with the desired exeptions. Problem : I am not able yet to build my own htaccess … :o(

A slight modification of timthumb.php in my Justified Image Grid plugin would satisfy more (or challenge me less …)

Thanks !