Private Sub List1_Click()
  RichTextBox1.SelStart = Len(RichTextBox1.Text)
  RichTextBox1.SelText = " " & List1.Text
End Sub
 
Private Sub List2_Click()
  RichTextBox1.SelStart = Len(RichTextBox1.Text)
  RichTextBox1.SelText = " " & List2.Text
End Sub

Private Sub List1_Click()
  Call TypeText(List1.Text)
End Sub
 
Private Sub List2_Click()
  Call TypeText(List2.Text)
End Sub
 
Private Sub TypeText(Text As String)
  RichTextBox1.SelStart = Len(RichTextBox1.Text)
  RichTextBox1.SelText = " " & Text
End Sub

Gruß
Marcus