more control over external link in new windows

I think it would be great if we can create a list of external link that open in the same page or not treated like external.

That the simple way, a more robust application would use a list of regular expression of domain to be treated as a internal link.

Ex. I have a virtual community. http://comunidad.cav.sld.cu with some associated sites that share user, login, search, etc, created with domain module. These sites are http://gescon.cav.sld.cu and http://caed.cav.sld.cu. All then are treated as external link, but actually there are from the same community.