You may be lucky enough not to need a driver as such. I managed to get a USB Zoom 3095 to work without using the provided driver, and just having my Ubuntu application talk to it using native AT commands.
What I would do is install wvdial ('sudo apt-get install wvdial') and then run 'sudo wvdialconf' to configure it. If all goes well you will end up with a file: /etc/wvdial.conf. One of the most useful bits of this will be where the modem 'is' as the system sees it. Look for the line similar to 'Modem = /dev/ttyACM0'.
Personally I use minicom to troubleshoot modems (install with 'sudo apt-get install minicom' but watch the configuration) and talk to it using AT commands, but you'll only really need to do that if the application you are using seems unwilling to talk to the modem.