It's easy to change, when I get back from work tonight I'll re-code a bit so it reads from a text file the numbers. Unless commas are used between each number, each number will have to be 2 digits. This is because it splits the code into 2 character sections, and converts them to numbers. I can change it to any number of digits if you prefer, but every number used will have to have the same number of digits. If commas or spaces are used to seperate the numbers, then this wouldn't be necessary, but it might be easier to de-crypt the message.
If you have any more requests, don't hesitate to ask.
Thomas