listbox help

[funkheads]

ok...i'm using this code to populate a list box with files from a certain directory:

Private Function Dir2(ByVal Path As String) As Variant
    'function for listing the skin names in the listbox
    Dim aList() As String
    Dim sDir As String
    Dim iIndex As Long
    If Right$(Path, 1) <> "\" Then Path = Path & "\"
    'List Directories Only
    sDir = Dir(Path, vbNormal)
    While Len(sDir)
        ReDim Preserve aList(iIndex)
        aList(iIndex) = sDir
        iIndex = iIndex + 1
        sDir = Dir
    Wend
    Dir2 = aList
End Function

Private Sub Form_Load()
    'start function for listing the skin names in the listbox
    Dim aDir As Variant
    Dim i As Long
    aDir = Dir2(frmMain.txtPath.Text)
    For i = 0 To UBound(aDir)
        frmMain.lstBitmaps.AddItem aDir(i)
    Next
    'remove the first 2 items:  "." and ".."
    frmMain.lstBitmaps.RemoveItem (0)
    frmMain.lstBitmaps.RemoveItem (0)
End Sub

is there anyway to make sure that only files with a certain extention show up in the box? thanks for your help.