How to increment if file exists?

[seraphicmortal]

Hello!! Hoping to get some more help here..
The code below can save a profile.

If the same filename exists, and the user chooses not to overwrite the file, I want to add -nn (-01, then if still the same filename will be -02, and so on and so forth) to the end of the file before the extension .plp.

example output:
filename.plp
filename-01.plp
filename-02.plp
filename-03.plp ~ filename-99.plp

This is my current code:

Function isFile(ByVal sFileName As String) As Integer
  On Error Resume Next
  Dim lFileLength As Long
  Const ATTR_NORMAL = 0
 
  isFile = False
  If Dir$(sFileName, ATTR_NORMAL) <> "" Then
  lFileLength = FileLen(sFileName)
  If (lFileLength > 0) Then isFile = True
  End If
End Function

Private Sub cmd_ok_Click()
Dim prof As String
Select Case Me.Caption
    Case "Save Profile"
    txt_profilepath.Text = file1.Path & "\" & file1.FileName & txt_plprofile.Text
        If isFile(txt_profilepath.Text) Then
            txt_plprofile.Text = frm_loadfile.var1
            prof = frm_field.GetString(txt_plprofile.Text, "-", "C")
                If MsgBox("File " & txt_profilepath & " exists.  Do you want to overwrite the current profile?{Y/N]", vbQuestion + vbYesNo, App.ProductName + " Prompt") = vbYes Then
                    SaveProfile txt_profilepath.Text, pl1
                Else
                    txt_profilepath.Text = file1.Path & file1.FileName & "\" & prof & "-02" & ".plp"
                    SaveProfile txt_profilepath.Text, pl1
                End If
        Else
            MsgBox "Saving " & txt_profilepath & " as new profile."
            SaveProfile txt_profilepath.Text, pl1
        End If
 
        profilepath = txt_profilepath.Text
        frm_field.cmd_next.Enabled = True
 
    Case "Load Profile"
        txt_profilepath.Text = file1.Path & "\" & file1.FileName
        MsgBox "Loading " & txt_profilepath & " profile."
            LoadProfile txt_profilepath.Text, pl1
        profilepath = txt_profilepath.Text
        frm_field.cmd_next.Enabled = True
End Select
    Me.Hide
End Sub

HELP!!..