So you have your open vpn as server working nicely? But you want your clients to appear on a differnt ip address on your server.

So for example i have:
80.0.0.1 setup as my eth0 address
80.0.0.2 as my eth0:1 address

I want my my vpn clients to be NATed through to eth0:1 not eth0.

Simple but sweet command from OpenVPN-AS support solved the issue nicely.

Login to your command prompt and do the following:

Make sure your logged in as root/sudo etc (su – / sudo )

cd /usr/local/openvpn_as/scripts
./confdba --mod --key vpn.server.routing.snat_source.0 --value eth0:1 (or which ever device you want your users to appear as)

Restart your server job done!
/etc/init.d/openvpnas restart

Now your clients should appear as 80.0.0.1 not 80.0.0.2
Feel free to ask any questions!