I suggest you find a nice introduction to Delphi, preferably a well written book. Learn enough about that to enable you to understand most of the statements in his five pages of Delphi code in his paper. You perhaps don't need to learn enough to be able to write programs in Delphi, just enough so you can understand programs someone else has written and gotten to run.
At the same time I suggest you try to understand enough about his non-code parts of the paper to roughly understand his encryption method.
While doing that perhaps you can sort through his code and see if you can identify and isolate a small part of the code that encrypts a single number or perhaps a single row of numbers.
If you can see how to separate all the stuff he has for buttons and input and output and I assume windows and other things like that then perhaps there may be only a page, or possibly even less, of code that actually encrypts a number. I'm always a fan of starting with the smallest possible task when doing something new. Can you correctly encrypt a single number? That would be an excellent start. I don't recall if he has a concrete example of encrypting a single number or a small row. If he has that then what you want to do is to be able to get exactly the same result he does. If he doesn't have that then (DO NOT tell him I sent you) try to contact the author and explain that you are just getting started and trying to understand and implement his code in a new language and you would really REALLY like to have an extremely simple first test case to verify your work. Perhaps if he is nice he will send you a paragraph of explanation and an unencrypted and encrypted list of numbers. That will be gold for you to use. Be REALLY polite when you contact this person and see if he will be nice to you.
Once you think you have simplified things down to just encrypting one number or one row and you can translate his Delphi into simple pseudocode the post another message with what you have done and what you don't understand and where you are stuck. Someone might be nice enough to provide you with hints then.