Is is possible to use http://www.cemetech.net/sc/ to type symbols like the number sign into a program?
Yes, this is possible. I have used this to get special symbols like the vertical bar | and omega Ω into calculator programs. You could also possibly create a program that contains only a string with many special characters, then you could Rcl the program into the place where you need the special character and delete the ones you don't need.
It doesn't look like that character is supported. If you are trying to display it on the home screen, you could do
Output(1,1,"ΔList(
Output(1,2,"VELOCITY
That way the desired word would output over the "List(" and display "ΔVELOCITY"
I believe that most, if not all, of the characters on the calculator are supported on Scourcecoder. You can search for the token on the right side of Scourcecoder.
"Δ" is supported. It must be written as "Delta". This means that any character can be used in the Input command.
A few tokens can be typed out. However, there are instances where "must" would be turned into "μst". To prevent this, type a backslash to prevent this ("m\ust").
Some tokens are preceded by a vertical bar, "|". Some are preceded by double carets "^^". Some are enclosed in square brackets. If you need a reference, search for the token on the right side of Scourcecoder.
TokenIDE is an offline alternative to Scourcecoder, an online text editor. The latest build can be found in this topic.
Here are two programs that might do just that.
TI-83/84 (+/SE): Charz v3.0
TI-84+CSE: Charz CSE