How do I do that when I click on a button (Command1) it will save the data on a ListBox (List1) and another button (Command2) will load it back? (On a TXT)

And also I got 100 Checkboxes in the same form (not in array).
How do I make it that Command1 saves this too on another TXT and Command2 loads it?
let's say I got 72 Checked so when I load it it will have 72 checked?

ThanX for any posts.