how to add openmeetings to owndomain

[Tess]

How can I attach the openmeetingsservice to the server which is hosting 
my domain? (such as: www.mydomain.com/openmeetings) It is working fine 
in my local network with my local IP, but I want my domain in the title 
and that it is reachable from outside the local network. I am no 
programmer and using windows 7. I would be very happy if someone can 
help me.
Tess