multi site serving images from domain different than $siteurl

Hi, is there any way for configuring the img src to link to a different domain than $siteurl?

I’m asking this because I need all images to be served from another webserver, over a cookieless domain, and still having the ability on wordpress editor to correctly link the uploaded image with it’s new domain.

I’m trying all kinds of setup with fileupload url, upload url path and upload domain to no avail. I’ve successfully made wordpress to write to a different upload dir, by relativisticly changing the upload dir to reach the cookieless domain NFS, but wordpress keeps linking all images to $siteurl domain.

thanks!