Nat internal IP:port to External IP:port

[mikromanager]

I've a new customer ho has a Cisco 7604 as Border Router. Internally he has several Mikrotiks (I used to work with Mikrotik also).

I need to block access to internet to an specific IP (internal) nat or forwarding traffic from that ip to specific ip... on port 80 !...

We are trying that unpaid customers get a UNPaid Website using a nat rule...

can anyone explain me how to do it ?

Thanks

[lmediavilla]

I don't think you can do that with nat, you can't either with PBR,  maybe WCCP is your best option but you need a proxy server that gets any  HTTP query and responds with the Please Pay website

kind regards