masquerade an URL - how to do that!?

good day dear linux experts - hello all opensuse friends



I would like to be able to masquerade an URL, that is to keep the URL the
user is entering when going to a page. For example:
The user is entering at his browser:

http://foo.mydomain.com

This must be forwarded to:

http://foo.otherdomain.com

But on his browser, the address displayed must stay http://foo.mycompanydomain.com
I would like to configure this - but how:!!?

Has anyone an idea how to proceed?