Add Selected Files From Listbox1 Over To Listbox2?

So I have two ListBoxes. Listbox1 gathers files from a directory and I have an add button to add selected files from Listbox1 over to Listbox2.

Is there a way to manually sort these items? Maybe with an up down buttons?

The reason I'd like to sort/reorder is I'll have a process that will run those selected files and each file will have to produce another file unique to the filename.

A quick example would be process FILE1.txt and produce FILE1.pdf, etc.

Is there an easier way to accomplish the sort/reorder?

UPDATE

Here is currently how I'm populating my listbox1, before adding anything to listbox2, which is the ListBox I'd like to have sorted so way or another.

Dim directoryInfo As _
New System.IO.DirectoryInfo(FolderBrowserDialog1.SelectedPath)
Dim fileInfos() As System.IO.FileInfo

[Code].....