SBS Exchange setup

I have register my domain with isp, they provide me a 10 e-mail accounts, I want this e-mail account box in local MS SBS server 2003 exchange server as well as on isp server. I have installed my sbs server with my same domain name which i register (company.com).

What steps should i have to follow to connect my isp mail server with my sbs exchange server.

Can i put 2 mail boxes at a different places

I want to send e-mail from my LAN to other networks

Regards
uv