Option Explicit

Private Declare Function GetLocaleInfo Lib "kernel32" _
        Alias "GetLocaleInfoA" (ByVal Locale As Long, _
        ByVal LCType As Long, ByVal lpLCData As String, _
        ByVal cchData As Long) As Long
Private Declare Function GetSystemDefaultLCID Lib _
        "kernel32" () As Long
Public Delimiter As String
Public ASCII_Delimiter As Long

Private Function GetEntry(ID&) As String
  Dim LCID&, Result&, buffer$, Length&
    LCID = GetSystemDefaultLCID()
    Length = GetLocaleInfo(LCID, ID, buffer, 0) - 1
    buffer = Space(Length + 1)
    Result = GetLocaleInfo(LCID, ID, buffer, Length)
    GetEntry = Left$(buffer, Length)
End Function

Private Sub Command1_Click()
Dim l As Long, i As Long
  Me.Text2.Text = ""
  l = Len(Me.Text1.Text)
  If l = 0 Then Exit Sub
  For i = 1 To l
    Select Case Asc(Mid(Me.Text1.Text, i, 1))
      Case ASCII_Delimiter, 48 To 57
      Case Else
        MsgBox "Ungültige Eingabe"
        Exit Sub
    End Select
  Next
  Me.Text2.Text = Me.Text1.Text
End Sub

Private Sub Form_Load()
  Delimiter = GetEntry(&HE)
  ASCII_Delimiter = Asc(Delimiter)
End Sub