Forward outgoing request to a remote server only for some destinations

[Telair23]

Hi to all, first topic here :P

I have:

- A dedicated server hosted in US, ip 1.2.3.4
- A VPS hosted in FR, ip 2.3.4.5

Both server have Linux/Debian, and only one ip each (eth0)

What i need:

All outgoing traffic from 1.2.3.4 exit normally to internet,
EXCEPT for destination IP X,Y,Z,etc, that i want to be done by 2.3.4.5 server.
The 2.3.4.5 it's dedicated to this, and accept connections ONLY from 1.2.3.4.

I'm newbie about networking.
I understand i need to create "route" in 1.2.3.4, and
enabling IP forwarding with some iptables rule (nat? masquerading?) in 2.3.4.5.

It's possible to do with only one IP on 2.3.4.5?

Thanks for help!

[Fishbone_Beat]

Maybe this can help, the command you are looking for is called "route" and you can use it with the following options (I only show here whats relevant to your goals:

add
add a new route.
target
the destination network or host. You can provide IP addresses in dotted decimal or host/network names.
-net
the target is a network.
-host
the target is a host.
netmask NM
when adding a network route, the netmask to be used.

So the command would be something like:

route add -net 123.45.67.0 netmask 255.255.255.0 dev eth0

eth0 being the interface you want to forward the packets to.