User Controls: Property attributes & design time visible controls

[KevoMee]

I have a property called CalendarURL on my control as below:

public virtual string CalendarURL
{
get { return m_URL; }
set { m_URL = value; }
}

Now at design time I want the User to be able to set this property by clicking on a button in the properties tab and selecting the required URL. (As you would when selecting URL for hyperlink control) Any ideas?

I also have a hidden field that I don't want the User to be able to see when they drag the control onto their form. How would I go about making this invisble?

Cheers.