Dim curPos as integer = -1

For i = 1 To n
   If i = m Then
      RichTextBox1.Text = RichTextBox1.Text & ss(i)
      RichTextBox1.SelectionStart = RichTextBox1.Find(ss(i), curPos +1, RichTextBoxFinids.WholeWord)
      RichTextBox1.SelectionFont = Bold
   Else
      RichTextBox1.Text = RichTextBox1.Text & ss(i)
   End If
   curPos = RichTextBox1.Length
Next