I know Celtic 3 has a function that can do it and since C3 is built into DoorsCS7, it can do it, too. I've also made programs, like CopyProg that does that among other things. However, these return the number in a variable instead of displaying the number of lines.
One thing that I have done with the tools I mentioned is to make a program viewer. From the code that you currently have, you could make it so that specific lines could be jumped to for viewing, as well as scrolling through the source line by line.
As well, Celtic 3 allows line reading, inserting, overwriting, and deleting. It would be neat if you could think of other functionalities!
