You will have to define your menu structure in software. There isn't a command for scrolling the text since there isn't buffer to store text that are "off the screen". If you want to display more than 4 lines, then implement a "page up" and "page down" using the function key. Use a variable to keep track of the page number and then display the corresponding text to the page.
Note that since the string A$ to Z$ an also be represented by an array $$[1] to $$[26] you may be able to store some text in the string variable and selective display them using the index n to the array $$[n].
