This is how to do it.

Download Wireshark (http://www.wireshark.org/download.html) - This is a program which can figure out the IP your PC interacts with - and install it.
Start it (for advanced users: do not capture now!)

Start the game by visiting the official BF:H Website and click the Big "Play Now" button.

Now select your character click "Play Now!" again. It doesn't matter on what server you land, because you won't stay there.
Press TAB+F5 or your custom key-combination to bookmark this server.
In the statistics board you should see the words "This server is bookmarked" at the top on the right.

Tab out with ALT+TAB and close any Programs (except Battlefield) which use the Internet or could use the internet. If you jump over this step, you won't be able to see clearly with which IP you communicate as a Server.

If you disconnected from this Server already, join it again by using the Options --> Connect to server Function.
Just be sure that you are in a normal play and the game generates traffic.

Now, run a Wireshark capture (if you have closed it, open it again!) by simply pressing Capture --> Interfaces on the Top Bar.

Now, search for the Device which got packages (here should be only one) - and select "start".

Tab back into the game by simply clicking on the BF:H logo in the Taskbar and play a bit.

When you think you got enough (5 Sec of real gameplay are enough most times), tab out again and enter the Wireshark GUI. Then click "Capture --> Stop" in the top bar.

Now you should only find about 3 IPs or less. Now you want to prove that you are proceeding with the right one, so let's see if it's a Eliot Ness Server for example. You can find out this by simply doing a TRACERT command in the CMD. Just open the Command Line ([WinKey]+[R], then enter CMD) and enter "tracert [ip-address]", so, in my example it could look something like this "tracert 95.122.188.128", just without the quotes. If you had success, you should see somewhere something like provider.eliot.ness (it doesn't have to look like this, but just find out if there is anything about a Server Provider). If you don't know any server providers, go here: Rent a Server - Free Shooter Game - Online shooter - Battlefield Heroes <-- These are the official Providers for official servers.
Now, we have got the IP of our server. We just have to redirect the IP of the server to an IP of our wishes...

can you solve this puzzle? please post and let everyone know!