Unzip only "text" files in a particular folder

Hi,
I got some code which will select multiple zipped folder and extract the files in the selected zip folder.
The given below code will extract all the files however i am trying to get all the (.txt files only) from the all selected zipped folder.
I tried but ended up with a mess. Can anyone help me on the same.
Please....



Sub Unzip4()
Dim FSO As Object
Dim oApp As Object
Dim Fname As Variant
Dim FileNameFolder As Variant
Dim DefPath As String
Dim strDate As String
Dim I As Long
Dim num As Long

Fname = Application.GetOpenFilename(filefilter:="Zip Files (*.zip), *.zip", _
MultiSelect:=True)
If IsArray(Fname) = False Then
'Do nothing
Else
'Root folder for the new folder.
'You can also use DefPath = "C:\Users\Ron\test\"
DefPath = Application.DefaultFilePath
If Right(DefPath, 1) <> "\" Then
DefPath = DefPath & "\"
End If

'Create the folder name
strDate = Format(Now, " dd-mm-yy h-mm-ss")
FileNameFolder = DefPath & "MyUnzipFolder " & strDate & "\"

'Make the normal folder in DefPath
MkDir FileNameFolder

'Extract the files into the newly created folder
Set oApp = CreateObject("Shell.Application")

For I = LBound(Fname) To UBound(Fname)
num = oApp.Namespace(FileNameFolder).items.Count

oApp.Namespace(FileNameFolder).CopyHere oApp.Namespace(Fname(I)).items

Next I

MsgBox "You find the files here: " & FileNameFolder

On Error Resume Next
Set FSO = CreateObject("scripting.filesystemobject")
FSO.deletefolder Environ("Temp") & "\Temporary Directory*", True
End If
End Sub