Your impatience is quite evident. The problem is Linux demands patience.
Did you look on the Red Hat site as I suggested? Even if it isn't a WinModem, their tech staff has probably configured it before. If the model number doesn't get a hit, try the type, such as External USB modem, External Serial Bus Modem, or whatever it is.
Also, go to
www.google.com/linux and search for those things.
www.tldp.org is The Linux Documentation Project, where people who have had to work through challenges with Linux post their solutions in documents called HOWTOs. Look through their files and see if someone has configured your modem or one like it.
Also, hidden at the top of the screen, where most folks are unable to find it, is a search button. In the search engine, see what is on this bulletin board already. For example, "US Robotics External Modem" came up with 55 hits other than yours.
When you've done all of this and it still doesn't work (which will surprise me), come back to this thread and post:
1. The make and model number of your modem
2. How it is connected (USB, Firewire, Serial)
3. The results of your research.
4. Based on that research, what you have tried and the results.