First, the positive, this program is very easy to use and would probably provide beginners with something to learn the basics of BASIC from. It does /almost/ everything it says. Truly, it only converts real positive integers to strings, not numbers.
Usability - 10/10
There is nothing wrong with the usability. The parameter passing is as expected.
Code - 2/10
The code is quite unoptimized with regards to size and speed. In short, his algorithm goes from right-to-left and converts the number to a string, then proceeds to flip the string around. There is absolutely no need for the post-process flipping when you can simply reorder the way in which you concatenate to the string.
Features - 5/10
It only comes through with half of the features it truly should offer! As I said before, it only converts positive real integers. At least it should include all integers. On top of that it should be able to convert decimals to a string as well.
Overall - 17/30
To be terse, roll ("write") your own implementation, or go to any comprehensive BASIC forum and ask around. I would definitely not download this program, unless the author updated it.