Function CountChar(ByVal sText As String, ByVal sChar As String) As Long
  Dim nCount As Integer
  Dim lPos As Long
 
  nCount = 0
  lPos = 0
 
  sText = LCase$(sText): sChar = LCase$(sChar)
  Do
    lPos = InStr(lPos + 1, sText, sChar)
    If lPos > 0 Then
      nCount = nCount + 1
    End If
  Loop Until lPos = 0
 
  CountChar = nCount
End Function

nCount = CountChar(Text1.Text, "f")