Just use the OSC multi transmit. Worked fine for me with ETC. The trick is really to figure out the adress for the command. There are some PDFs out there from ETC. I attached one but there are more out there.
Here is a user actor form one of my old patches that might need some dissecting, but hopefully you can extract the general idea
Also, if you just want to type in numbers, you just simulate it by sending the right osc adress and digit (in the "input" field) with a short delay inbetween.
746361-etc-channel.iua c8d85d-eos-osc-keys.pdf