Here is some code that loops through a multiselection listbox. The Debug.Print line sends the results to the Immediate Window. You can see the results in the immediate window. You can view the immediate window by using Ctrl+G on your keyboard.
You will need to replace the correct name for your listbox.
Code:
Dim varSelection As Variant
Dim lngID As Long 'Assumes the value in the first column is a number
If Me.List0.ItemsSelected.Count = 0 Then
Exit Sub
Else
For Each varSelection In Me.List0.ItemsSelected
lngID = Me.List0.Column(0, varSelection)
'Insert code here to do something
Debug.Print lngID
Next varSelection
End If