Is this somehow possible?

We are running Apache 2.0.55 in Windows 2000 server like
ourserver.organization.org. There is a redirection (virtual directory)
our_group on the web server (IIS, www.dep.organization.org) of the
department to our Apache server. When the user requests our web pages
(www.dep.organization.org\our_group) the redirection works fine but the
address in the browser changes to ourserver.organization.org. This a default
feature but is there any way to configure our Apache server to show
www.dep.organization.org\our_group in the address box of the browser
instead?