As mentioned, you can make a request, but if someone else makes the extension, they cannot test it unless they have an appropriate modem.
You could experiment yourself. (I am not sure how successful you will be.)
Extract it like this
tar -zxvf /path/to/tar.gz-file
You may need to do more than extract it. I am not familiar with the particular driver. See if there is any info where you get the driver, or in a file within the driver.
To make a new extension you need the squashfs-tools-4.0 extension installed.
Create a directory for your new extension. For Example:
mkdir -p /home/tc/myext/
Paste all files and directories for the new extension to /home/tc/myext/.
To create an extension:
sudo su
cd /home/tc
mksquashfs myext/ name-of-new-extension.tcz
Paste the new extension to the /tce/optional directory.
Include it in On Boot or On Demand.
To start it, you may need to use an appropriate command in the terminal.
If you do get it working, share what you learn.