People have complained about the limitations of cableTV access in the past, and no real help seems to have come from their comments. Since I know virtually nothing about how it works, of course I'm fully qualified to offer blithering opinions. I have no idea if I can offer anything helpful.
If you see text and, as is obvious from your post you can write text, it should be possible for you to write the text for a clicky if you have the characters required.
The normal and vastly oversimplified pitch on how it all works, is that you send plain text to mudcat, and it's the html wizard at mudcat - and at the machine that receives and reads it - that turns the correct text into a clicky.
The "strange" characters you need to be able to "type" are just < and > and /.
in theory, you should get a clicky when it's posted at mudcat.
Your screen should show somewhere the "URL" for the thing you want to link, probably labelled as an "Address" for the site you want to link to. The "WhatYouWantToShow" is what will be blue - and what others will click on - to go to your link.
Note that I don't really have any idea whether this will work, but its a good theory to start with.(????)
Perhaps one of those with a similar setup will be along in a while.