
Código (html4strict) [Seleccionar]
<select name=color class=selectbox>
<option value="1">Verde</option>
<option value="2">Rojo</option>
<option value="3">Azul</option>
<option value="4">Amarillo</option>
</select>
Entonces:
CitarWebBrowser1.Document.All.Item("color").Value = "1"
Saludos!