I was just reading the w3 schools definition of what base url does. I can see that if you specify an absolute path for your images in the base url (eg.<base href="http://www.w3schools.com/images/" />), all you need to do is reference the image filename and the baseurl will complete the filepath to your images for you.What I want to know is, can you override that by specifying an absolute path in order to reference a file or indeed page from elsewhere?
are you asking that you want to use another absolute path outside your server for a page?
I don't use base href anymore (I setup absolute paths via my htaccess file) so not sure if it would affect your link if you added an absolute path there.
I do know however it does work correctly via htaccess.
For example I have all of my site links to preface with http://www.atseadesign. The URL part of my image or link then has /directory/file.
But in other areas of my site I use an absolute path without any problems. i.e. http://twitter.com/blahblah
I guess the best way to see if it works is throw it in there and try it.