Calcul d'occurrences en VB6

Private Sub Command1_Click()
    Dim Chaine, Nblettre As Long, lettre As String
    Dim obn As Object, cle As String, cles, k As Long, n As Long
    
    Chaine = "aAbBcC"
    Chaine = UCase(Chaine)
    Set obn = CreateObject("scripting.dictionary")
    For x = 1 To Len(Chaine)
        cle = Mid(Chaine, x, 1)
        If Not obn.Exists(cle) Then obn.Add cle, 1
    Next x

    cles = obn.keys
    n = obn.Count
    For k = 0 To n - 1
        lettre = cles(k)
        Nblettre = 0
        For x = 1 To Len(Chaine)
            If Mid(Chaine, x, 1) = lettre Then
                Nblettre = Nblettre + 1
            End If
        Next x
        MsgBox "le fichier contient la lettre " & lettre & " " & Nblettre & " fois ", vbInformation, vbOKOnly
    Next k
End Sub

Private Sub Command2_Click()
    Set mondico = CreateObject("Scripting.Dictionary")
    Chaine = "aAbBcC"
    Chaine = UCase(Chaine)
    For x = 1 To Len(Chaine)
        cle = Mid(Chaine, x, 1)
        mondico(cle) = mondico(cle) + 1
    Next x
    TLettre = mondico.Keys
    TNblettre = mondico.Items
    For x = 0 To mondico.Count - 1
        MsgBox "le fichier contient la lettre " & TLettre(x) & " " & TNblettre(x) & " fois ", vbInformation, vbOKOnly
    Next x
End Sub

Option Explicit

Private Sub command1_Click()
Dim chaine As String 'ma chaine de caractères
Dim I As Integer
Dim J As Integer
Dim TC(0 To 255) 'tableau des caractères

On Error GoTo erreur
Dim MyFile As String
MyFile = App.Path & "\hello.txt"  'le fichier texte
Open MyFile For Input As #1
     Line Input #1, chaine
Close #1
    Text1.Text = chaine
    For i = 1 To Len(chaine)
        For J = 0 To 255
            If Mid(chaine, i, 1) = Chr(J) Then
                TC(J) = TC(J) + 1
                Exit For
            End If
        Next J
    Next i
    
For J = 0 To 255
    Cells(J + 1, 8).Value = Chr(J) 'renvoie dans la colonne H le caractère (à adapter)
    Cells(J + 1, 9).Value = TC(J) 'renvoie dans la colonne G le nombre de caractères (à adapter)
Next J
'
'
'        If Mid(chaine, i, 1) = "a" Or Mid(chaine, i, 1) = "A" Then
'         nombredea = nombredea + 1
'         End If
'   Next i
'MsgBox "le fichier contient la lettre A " & nombredea & " fois ", vbInformation, vbOKOnly
Exit Sub
erreur:
MsgBox "Fichier introuvable", vbExclamation
End Sub