Option Explicit
 
Dim txtbreite As Long
 
Private Sub Form_Load()
    txtbreite = 3000
End Sub
 
Private Sub Text1_Change()
 
    Dim zeilen() As String
    Dim tmpN As Long
    Dim tmpX As Long
    Dim CharNum As Long
    Dim curTextWidth As Long
    Dim Counter As Long
    Dim SelStart As Long
 
    SelStart = Text1.SelStart
    zeilen = Split(Text1, vbCrLf)
    For tmpN = 0 To UBound(zeilen)
        If tmpN >= 3 Then Exit For ' max 3 - zeilen
        curTextWidth = Me.TextWidth(zeilen(tmpN))
        If curTextWidth > txtbreite Then
            Counter = 1
            Do
                If Me.TextWidth(Left(zeilen(tmpN), Len(zeilen(tmpN)) - _
                  Counter)) <= txtbreite Then
                    CharNum = 0
                    If tmpN <> 0 Then
                        For tmpX = 0 To tmpN - 1
                           CharNum = CharNum + Len(zeilen(tmpX)) + 2
                        Next tmpX
                    End If
                    CharNum = CharNum + Len(zeilen(tmpN)) - Counter
                    Text1.Text = Left(Text1.Text, CharNum) & vbCrLf & Right( _
                      Text1.Text, Len(Text1.Text) - CharNum)
                    If SelStart > CharNum Then
                        SelStart = SelStart + 2
                    End If
                    Exit Do
                End If
                Counter = Counter + 1
            Loop
        End If
    Next tmpN
    Text1.SelStart = SelStart
 
End Sub