Regular Expression for Number Range validation in ASP.Net

Please refer this link

 http://utilitymill.com/utility/Regex_For_Range.

I have generated the expression from the above link.

<asp:TextBox ID="txtNumber" runat="server" />
<asp:RegularExpressionValidator ID="Regularexpressionvalidator1" ControlToValidate="txtNumber"
    runat="server" ValidationExpression="\b([2-9][0-9]{2}|[1-9][0-9]{3,8})\b" ErrorMessage="RegularExpressionValidator"></asp:RegularExpressionValidator>