See
http://www.gmayor.com/Userform.htm and in particular the FillBM function then you need something like.
Code:
Private Sub CommandButton1_Click()
With ActiveDocument
If UCase(TextBox1.Text) = "YES" Then
FillBM "Text1", "The cow is green"
Else
FillBM "Text1", "The cow is not green"
End If
End With
Unload Me
End Sub