You will have to either update to a new kernel that supports that dongle or use another wifi dongle that works with wheezy.
I assume that is a usb dongle?
Another option is to install Linux Mint 17.3 or 18.1 and install linuxcnc yourself? Linux Mint works well and things just work.
Look further in this form JT has a howto with 17.3 and I have one for 18.1. Another option is to try and load the driver yourself reading about that particular dongle and others that have got it to work for them.
