Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Str() As String
Dim i, j As Integer
Str = RichTextBox1.Text.Split(";")
For i = 0 To Str.Length - 2
j += 1
TextBox1.Text &= Str(i) & ";"
If j = 10 And i <> Str.Length - 2 Then
TextBox1.Text &= vbCrLf
j = 0
End If
Next
End Sub