The COM3 device would be /dev/ttyS2 under Linux, but bare in mind that
this is probably a virtual port under Windows and therefore won't map
directly to a Linux device at all. IIRC the driver for the adapter
creates the COM device, which is basically a hack to allow Windows-based
programs to "see" an extra serial port which doesn't actually exist.
Under Linux, /dev/ttyS2 represents an *actual* serial port, should you
have it (which you don't).
However - the kernel module usb-serial supports a lot of these adapters.
You did the right thing posting all the details and model numbers, but
seem to have missed the important one ;-) Supported devices are listed
in the kernel source docs under: Documentation/usb/usb-serial.txt
You should end up with devices like /dev/usb/ttyUSB0, which you can then
use as if there were regualr serial ports.
Another place to look for details would be here:
On my system (Debian Sarge) the module isn't compiled by default. This
may be different in Fedora but otherwise you'll need to compile it yourself.
Best of luck,
Den Haag, The Netherlands