How to add a control to a masterpage contentplaceholderprogramattically

[DotNetNewbie]

Hello,

Say I want to override the current page's masterpage file, and I also
want to programatically load a user control and inject the control in
the master page's controlplacehol der.

How would I do this?

I am doing:

protected override void OnPreInit(Event Args e)
{
base.OnPreInit( e);

MasterPageFile = "~/Themes/Default/portal.Master";

}


Now how do I inject a user control in the MasterPageFile' s
contentplacehol der with ID="content"?