So,before closing your application,you want to save the contents of all your list boxes in a single file and load them back into the respective list boxes on starting the application?Correct?
Assuming i am correct,
Just save the contents of the list boxes in a single text file.Like,
a.b.c*d.e.f.g*i.j.k*........
here a,b,c belong to listbox1,d,e,f,g belong to listbox2 and so on..
all you have to do is open the text file and read its characters one by one.
if you encounter a '.',the characters following it must be included in a new listindex of the current listbox.
if a '*' is encountered,the following characters must be included to listindex=1 of the next listbox.