Can you give us some more information about the server.
- In what format are the maps available? (bitmap? vector? bitmap-tiles?)
- Do you need special authentication/password to access it? how?
Could you perhaps give us a link to the provider so we can investigate further.
We're working on making it easier to hook up to custom map(tile)-servers (same format Google & yahoo etc use) but if the maps aren't accessible in bitmap-tile format then you need to make such a middle-service available. (Franson GpsTools Studio can calibrate maps and create tiles if you have "raw-data" map information.)