The bind address is the IP address you want MySQL to listen on.
It has to be an IP address on the server.
So if ifconfig shows you have IP addresses
You can make MySQL listen to requests from the big wide world by binding it to 188.8.131.52,
If you want to only listen to requests on your LAN, set the bind-address to 192.168.1.14 and
If you want MySQL to only listen to clients on the same server set the bind-address to 127.0.0.1
If you need to listen on more than one interface (say LAN, localhost and internet) then comment out the line so MySQL listens on all interfaces.
If you do allow connections from the internet, then use IP tables (or ufw) to only allow connections to port 3306 from the IP of your remote client PC at the office.