dsl modem

so a have a dsl modem which has a ethernet port, which is connected to a router to 2 other computer, and a usb port
do you think if i bought a usb to cat5 adapter and plugged it into with a wireless router, would it work
it's just that my current router's settings are perfect and i don't want to change anything, so this might be a good wireless solution, at the same time i think it would logically word, but dunno about the adapter part

any info would help

What, do you mean the modem has a USB port on it as well as the ethernet one? No, that USB port is intended for direct connection to the computer, not through a USB-RJ45 adapter (technically there is no such thing - USB-RJ45 ethernet "adapters" are essentially network cards that plug into a USB port and, like any NIC, require OS-specific drivers to work). Unless I've misunderstood the specifics of your question, no, it won't work.