Here's the basics in DAO code. You will have to modify field and table names to suit.
No error handling in this, so you should add your own.
Sub GetData()
Dim ctl As Control
Dim varItm As Variant
'set up a recordset
Dim db As Database
Dim rs As Recordset
Dim sql As String
sql = "tblMyTable" 'sql is a table or query name, or a sequel string
Set db = CurrentDb
Set rs = db.OpenRecordset(sql)
ctl = Me.ListBox
For Each varItm In ctl.ItemsSelected
'Debug.Print ctl.ItemData(varItm)
'do your dirty work here
'new record
rs.AddNew
rs.FieldName = ctl.ItemData
'save it
rs.Update
Next varItm
'clean up the recordset stuff
rs.Close
Set rs = Nothing
Set db = Nothing
End Sub
"The Key, The Whole Key, and Nothing But The Key, So Help Me Codd!"