F5 Redirection over Public Networks

What I can see is that when I hit from external:

 

http://test.public.domain/odt

 

I get correctly redirected to the internal

 

http:/test..domain/odt

 

 

But the external user does not know how to reach the internal domain.

 

Rather than a redirect rule I need a rule that forwards requests from the public domain to the internal domain like the Microsoft ISA Reverse Proxy is capable of doing.

 

While doing the forward the external user should always place the requests via the public domain rather than being redirected to the internal domain.

 

 

We have this working on Microsoft ISA but I'd like to migrate the same feature over to F5.