To do that, you need to save the controls you added, what type they are, the place you added them, and all the other info you set when you added them; and store that info in a file - the read it back at startup and add them again.
We can't do that for you: we have no idea what you code is doing, how it does it, or when it does it. So start by picking a sensible file format (XML, or JSON maybe) and store the data in a sensible place:
Where Should I Store My Data?[
^] - to code is in C#, but it's pretty obvious stuff.
Submit an article or tip