[VB.NET] Compressione di diversi file RTF in un unico file

[mircome]

ho la seguente routine che mi compatta diversi file RTF un unico RTF. Funziona benissimo ma anziché visualizzare il file compattato al termine dell'esecuzione desidero salvarlo in una cartella con un nome da me scelto.
(come riportato al termine del codice)
grazie per l'aiuto.
il codice è il seguente:

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click


Dim fileArray As New ArrayList
Dim intCount As Integer = 0


DirLav = TextBox2.Text
Dim dirInfo As DirectoryInfo = New DirectoryInfo(DirLav) ' mancano nel codice
Dim fiArr As New Microsoft.VisualBasic.Collection() ' mancano del codice


'== Create an object of WORD.


Dim objWord As New Microsoft.Office.Interop.Word.Application
Dim str As String = ""


'== Loop through the collection of documents and add to main word document


For Each fi As System.IO.FileInfo In dirInfo.GetFiles("*.rtf") ' dirInfo : is the directory where all the separate docs are saved


If Not fileArray.Contains(fi.FullName) Then ' Check if document is not already added.
If intCount = 0 Then
objWord.Documents.Add(fi.FullName) ' for the first document to be added use Documents.Add method
Else
objWord.Selection.InsertBreak()
objWord.Selection.InsertFile(FileName:=fi.FullName , Range:="", ConfirmConversions:=False, Link:=False, Attachment:=False) ' next time onwards use InsertFile method


End If


objWord.Selection.EndKey(Unit:=6) ' set the control \ cursor to the end of the document to insert next in the new page




intCount += 1 ' increment count by 1
fiArr.Add(fi.FullName) ' add the merged document to the collection


End If


Next


'== Delete all separate documents from folder after merge


For Each fi As System.IO.FileInfo In dirInfo.GetFiles("*.rtf")
fi.Delete()
Next


'== Make the main document visible
'************************************************* ***************
' anzichè semplicemente rendere il file compattato visibile io vorrei archiviarlo su una cartella a piacere es : "C:\Users\mirco\Desktop\Kdrill\stampertf"
' e con un nomefile di tipo rtf a mia discrezione es: "fattura.rtf"


'************************************************* ***********


If Not objWord.Visible Then
objWord.Visible = True
End If
End Sub