Confusion over IP/DNS address for remote hosting

[Steverino]

Excuse my ignorance about networking issues, but here goes: I'd like a user to open a remote host to get into their company's network when they're out of the office. The IP address I have doesn't seem to work, and the DNS name I have ("xCompany.com") also doesn't work. Does this have something to do with the company's firewall? How do I figure out what address to use for a served database when prompted to specify the host?

In a related issue, I've published the database via a workstation that has the database files open. While at the company, I can just enter the workstation's ip address, and view the database on the web. Outside the company, that doesn't work. How do I figure out the right address? Is it "http://xCompany.com/something:591"? How do I figure out the "something"?

(I'll also post this question in the web publishing forum.)