I'm not sure if this is an option I click somewhere or a plugin. I used to have it so that on my info pane it would show the characters in my command line, but when I switched computers it isn't there anymore and I can't remember how I set it up.
It worked OK for me. Here it is, turned into a plugin:
To save and install the Show_Characters_Typed plugin do this:
Copy the code below (in the code box) to the Clipboard
Open a text editor (such as Notepad) and paste the plugin code into it
Save to disk on your PC, preferably in your plugins directory, as Show_Characters_Typed.xml
The "plugins" directory is usually under the "worlds" directory inside where you installed MUSHclient.
Go to the MUSHclient File menu -> Plugins
Click "Add"
Choose the file Show_Characters_Typed.xml (which you just saved in step 3) as a plugin
Click "Close"
Save your world file, so that the plugin loads next time you open it.
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE muclient>
<!-- Saved on Saturday, September 10, 2016, 8:12 AM -->
<!-- MuClient version 5.02 -->
<!-- Plugin "Show_Characters_Typed" generated by Plugin Wizard -->
<muclient>
<plugin
name="Show_Characters_Typed"
author="Worstje"
id="22b61a28a371832a5d226960"
language="Lua"
purpose="Show how many characters in the command line"
date_written="2016-09-10 08:11:36"
requires="4.50"
version="1.0"
>
</plugin>
<!-- Script -->
<script>
<![CDATA[
function OnPluginCommandChanged()
-- OnPluginCommandChanged() gets called each time
-- the command window changes.
SetStatus("Character count: " .. GetCommand():len())
end
]]>
</script>
</muclient>