New Post: Adding regular expression validator to a Razor Function property?

Does anyone know how to do this?

I am setting the widget markup like so:

[FunctionParameter(
    WidgetMarkup = "<f:widgetfunction name=\"Composite.Widgets.String.TextBox\" xmlns:f=\"http://www.composite.net/ns/function/1.0\"></f:widgetfunction>")]
public string PropertyName { get; set; }

I am trying to figure out how to add a regular expression validator definition to this widget. I can see a regular expression function is available:

<f:function name="Composite.Utils.Validation.RegularExpressionValidation" xmlns:f="http://www.composite.net/ns/function/1.0">
  <f:param name="pattern" value="[Required Value]" />
</f:function>

Does anyone know how to do this?

Ta x