SQL Express * urgent cant setup remote connections

I am trying to setup a SQL Express box on a new dedicated server. The trouble is I cannot remote connect to it - I have done all of the obvious things - i.e. allowing remote connections etc. Enabling the browser and open port 1433 on the firewall. Everything works OK locally - I can connect with Studio Express etc . etc. This must be a breeze for somebody - but my lack of expereience means it could take me a while and I need it running quickly.